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Killer Sudoku

Killer Sudoku

Studio Goya LLC

Handcrafted Killer Sudoku puzzles by the most popular Sudoku channel!

4.5 Ratings 200+ Reviews 5K+ Downloads

Ratings & Reviews

Write a Review
  • Another great entry with good app improvements Dec 14, 2020

    By Jdesurra
    I’ve been a big fan of the Cracking the Cryptic apps, and this one is the best iteration so far. The author line up is great with Christopher Seeliger leading off the puzzles. The killer cages are easily visible, and the themes are a good mix of colors. Like the Sandwich Sudoku app, there is a column to show possible combinations in cages for those of us who struggle with mental math. There are 40 puzzles to start, which I think will keep most solvers busy for a bit. The only downside was I was hoping there would be some little killer puzzles, but it doesn’t look like there are any. That’s a bit of a nitpick since that was never really promised, but it would have been fun to see since combo killer-little killers are quite fun. In case case, this is well worth the money. Another great addition to the CtC app collection.
  • Jun 7, 2021

    By Emily Fatima Yunan
    Great puzzles with very informative step by step hints, very worthy purchase. Only issue is it takes up a lot of battery and gets really hot when running. Please make it more efficient if possible, can't imagine why it would be so computationally intensive especially if most of the time it's just waiting for input.
  • Not your average killer sudoku Dec 22, 2020

    By Jtersesk
    Killer sudoku is my favorite sudoku variant, and when I heard Cracking the Cryptic was releasing their own app, I was thrilled. As with their other apps, every single puzzle is hand-crafted and tested, and the creators themselves have written a series of hints for each puzzle that not only help you find the next step if you’re stuck but actually teach you techniques to improve your skills. Every puzzle in this app is absolutely extraordinary. They’ve been constructed by some of the world’s best setters. This is NOT your average killer sudoku. The logic involved is unique and exciting to find. Plus, the app has every feature I could ask for in a sudoku app: double notation, your choice of error-checking options, the ability to highlight and color, undo and redo. And specific to killer, it will add up cage totals for you, and it gives a list of all possible combinations for a given cage, and has a calculator for you to test other combinations. It’s a magnificent app, and well worth the $5. My only real complaint is the occasional typo in the hints, but it hardly mars the overall experience. Also, if there were a way to view the hint and the grid at the same time, that would be helpful.
  • Top Notch May 23, 2021

    By Dave Wooldridge
    I really appreciate all of Cracking the Cryptics sudoku apps, and this is one of my favorites. I enjoy that the puzzles in the beginning teach you the particular logic that you’ll need for more challenging puzzles (like how the first puzzle teaches you to use The Secret). One aspect I really like is the app does a lot of accounting aspects for you, like giving you possible combinations for a given killer cage along with a calculator, plus automatically removing pencil marks that a placed digit interacts with. That is the developers respecting the intelligence of the solver; the challenge is deductions, not getting buried under your pencil marks or petty arithmetic. Top notch app, hats off to the setters who contributed and the development team.
  • Apr 20, 2021

    By Ben Graham
    It's hard. I'm not sure if it's too hard; the people getting this are likely to be more advanced players....but it's still very hard. Having watching a ton of CTC I feel I have a slight advantage, but once again, it's HARD! That does mean there's likely great value in this - the 5th puzzle took me an hour and 20 minutes. Point of for the immediate end screen. I want to see what I've just completed.
  • Tough but excellent puzzles Jun 5, 2021

    By dsmarley
    A great app for when I’m looking for a really tough puzzle to chew on for an hour. One of the few puzzle apps where I don’t feel too guilty about resorting to a hint now and then. Or if eight or nine minutes go by and I can’t find a logical deduction that’ll move me forward, the app makes it possible to make a guess as to a digit in a particular box and see where it leads. I color the box before I make my guess as to its contents, so that if I reach a contradiction, I can quick undo my moves until the color disappears and I’m back where I started. Very handy. Speaking of hints, though, the first hint in puzzle #22 is in error. One suggestion: When one taps on a box, all the other boxes that that box “sees” are shaded. I’d find it helpful if the other boxes within the same cage could shaded in a slightly different color.
  • May 19, 2021

    By Timothy Baize
    The puzzles are gonna be hard. You aren't going to be able to immediately put digits into the grid. I will let you in on a few secrets 1-9 added up equals 45 and you should know about the phistomfel ring. All of these are things I learned from cracking the cryptic youtube channel. Just because this is CtC I know for a fact these puzzles have unique solutions and logical solution paths, no bifurcation necessary. Be patient with the puzzles and don't worry about time.
  • Difficulty curve too steep Jan 5, 2021

    By ConfusedSky
    One thing I’ve liked about the CTC apps is that they generally have a pretty gracious difficulty curve where you slowly get introduced to more concepts relating to the sudoku variant. Consequently, I’ve found it a bit harder to develop an intuition for this one. I felt almost completely lost after the first few. Of course I’m still learning, but I’ve had to view the hints quite a bit. I think for example after you get the 12 cage in puzzle 5 the logic is quite accessible most people would be able to figure it out. However getting that cage is a multi step process where you have to look quite a bit ahead to understand. I definitely don’t think that deserves to be a 3 star puzzle for that reason.
  • May 24, 2021

    By sampath kumar
    A thoroughly enjoyable puzzle that will be enjoyed by anyone that likes maths based puzzles. Very user friendly software to edit, colour, undo the grid. Like all the apps from the cracking the cryptic group this too is fantastic.
  • Another Killer App - Puzzles do not get better! Dec 16, 2020

    By Zegres
    These are the best Killer Sudoku puzzles you will ever solve. They are not created by an algorithm like so many apps, these are hand crafted by some of the best sudoku setters in the world. Each one takes you on a journey where you discover new tricks and ideas. The interface is great, the hints are very strategic and handmade as well. Just 6 months ago I was not aware of the world of handcrafted Sudoku puzzles. Now, because of the Cracking the Cryptic You Tube channel, I can’t get enough. Keep it up guys!
  • Another great entry with good app improvements Dec 14, 2020

    By Jdesurra
    I’ve been a big fan of the Cracking the Cryptic apps, and this one is the best iteration so far. The author line up is great with Christopher Seeliger leading off the puzzles. The killer cages are easily visible, and the themes are a good mix of colors. Like the Sandwich Sudoku app, there is a column to show possible combinations in cages for those of us who struggle with mental math. There are 40 puzzles to start, which I think will keep most solvers busy for a bit. The only downside was I was hoping there would be some little killer puzzles, but it doesn’t look like there are any. That’s a bit of a nitpick since that was never really promised, but it would have been fun to see since combo killer-little killers are quite fun. In case case, this is well worth the money. Another great addition to the CtC app collection.
  • Jun 7, 2021

    By Emily Fatima Yunan
    Great puzzles with very informative step by step hints, very worthy purchase. Only issue is it takes up a lot of battery and gets really hot when running. Please make it more efficient if possible, can't imagine why it would be so computationally intensive especially if most of the time it's just waiting for input.
  • Not your average killer sudoku Dec 22, 2020

    By Jtersesk
    Killer sudoku is my favorite sudoku variant, and when I heard Cracking the Cryptic was releasing their own app, I was thrilled. As with their other apps, every single puzzle is hand-crafted and tested, and the creators themselves have written a series of hints for each puzzle that not only help you find the next step if you’re stuck but actually teach you techniques to improve your skills. Every puzzle in this app is absolutely extraordinary. They’ve been constructed by some of the world’s best setters. This is NOT your average killer sudoku. The logic involved is unique and exciting to find. Plus, the app has every feature I could ask for in a sudoku app: double notation, your choice of error-checking options, the ability to highlight and color, undo and redo. And specific to killer, it will add up cage totals for you, and it gives a list of all possible combinations for a given cage, and has a calculator for you to test other combinations. It’s a magnificent app, and well worth the $5. My only real complaint is the occasional typo in the hints, but it hardly mars the overall experience. Also, if there were a way to view the hint and the grid at the same time, that would be helpful.
  • Top Notch May 23, 2021

    By Dave Wooldridge
    I really appreciate all of Cracking the Cryptics sudoku apps, and this is one of my favorites. I enjoy that the puzzles in the beginning teach you the particular logic that you’ll need for more challenging puzzles (like how the first puzzle teaches you to use The Secret). One aspect I really like is the app does a lot of accounting aspects for you, like giving you possible combinations for a given killer cage along with a calculator, plus automatically removing pencil marks that a placed digit interacts with. That is the developers respecting the intelligence of the solver; the challenge is deductions, not getting buried under your pencil marks or petty arithmetic. Top notch app, hats off to the setters who contributed and the development team.
  • Apr 20, 2021

    By Ben Graham
    It's hard. I'm not sure if it's too hard; the people getting this are likely to be more advanced players....but it's still very hard. Having watching a ton of CTC I feel I have a slight advantage, but once again, it's HARD! That does mean there's likely great value in this - the 5th puzzle took me an hour and 20 minutes. Point of for the immediate end screen. I want to see what I've just completed.
  • Tough but excellent puzzles Jun 5, 2021

    By dsmarley
    A great app for when I’m looking for a really tough puzzle to chew on for an hour. One of the few puzzle apps where I don’t feel too guilty about resorting to a hint now and then. Or if eight or nine minutes go by and I can’t find a logical deduction that’ll move me forward, the app makes it possible to make a guess as to a digit in a particular box and see where it leads. I color the box before I make my guess as to its contents, so that if I reach a contradiction, I can quick undo my moves until the color disappears and I’m back where I started. Very handy. Speaking of hints, though, the first hint in puzzle #22 is in error. One suggestion: When one taps on a box, all the other boxes that that box “sees” are shaded. I’d find it helpful if the other boxes within the same cage could shaded in a slightly different color.
  • May 19, 2021

    By Timothy Baize
    The puzzles are gonna be hard. You aren't going to be able to immediately put digits into the grid. I will let you in on a few secrets 1-9 added up equals 45 and you should know about the phistomfel ring. All of these are things I learned from cracking the cryptic youtube channel. Just because this is CtC I know for a fact these puzzles have unique solutions and logical solution paths, no bifurcation necessary. Be patient with the puzzles and don't worry about time.
  • Difficulty curve too steep Jan 5, 2021

    By ConfusedSky
    One thing I’ve liked about the CTC apps is that they generally have a pretty gracious difficulty curve where you slowly get introduced to more concepts relating to the sudoku variant. Consequently, I’ve found it a bit harder to develop an intuition for this one. I felt almost completely lost after the first few. Of course I’m still learning, but I’ve had to view the hints quite a bit. I think for example after you get the 12 cage in puzzle 5 the logic is quite accessible most people would be able to figure it out. However getting that cage is a multi step process where you have to look quite a bit ahead to understand. I definitely don’t think that deserves to be a 3 star puzzle for that reason.
  • May 24, 2021

    By sampath kumar
    A thoroughly enjoyable puzzle that will be enjoyed by anyone that likes maths based puzzles. Very user friendly software to edit, colour, undo the grid. Like all the apps from the cracking the cryptic group this too is fantastic.
  • Another Killer App - Puzzles do not get better! Dec 16, 2020

    By Zegres
    These are the best Killer Sudoku puzzles you will ever solve. They are not created by an algorithm like so many apps, these are hand crafted by some of the best sudoku setters in the world. Each one takes you on a journey where you discover new tricks and ideas. The interface is great, the hints are very strategic and handmade as well. Just 6 months ago I was not aware of the world of handcrafted Sudoku puzzles. Now, because of the Cracking the Cryptic You Tube channel, I can’t get enough. Keep it up guys!
  • Mar 29, 2021

    By Jeroen van den Broek
    Even the supposedly easiest puzzles are way harder than the easiest puzzles in the other CTC apps and in this app the hints are even worse than in the other apps. If you get stuck, forget looking at the hints to help you out. Half the time they mention a wrong row or column number and most of the time there are steps in the logic that aren't easy to see that are completely skipped in the hints. All of the other apps are nice but I can't recommend this one for anyone who's new to killer sudoku.
  • Apr 23, 2021

    By Ryan Harvey
    The puzzles are terribly designed for use on a phone. Most require summing pen and paper or a switching back and forth between a calculator and the app. I shouldn't have to be solving systems of equations to complete a puzzle that is designed to work on the phone which is exactly what the hints say to do. Loved the original app. This is tedious and takes the fun out of solving the puzzles.
  • Dec 29, 2020

    By Mattias Sossna
    This one is way harder then the others (and several of the tips have mistakes in them), I also found a lot of the pussel to be really boring (some are really good on the other hand) and not to the standards of previous titles... Sadly you're forced to play the bad puzzles to continue... Killer Sudoku is my favorite sudoku variant so really disappointing in this app....
  • Game#2 has bad cages that can’t be solved Jan 27, 2021

    By Tolator
    Lower left square has 3 cages with one space left and yet the total is already 45. So can’t solve puzzle 2, which is required to get enough stars to move to puzzle 3. Checked for updates to fix problem but none available.

No reviews available

No reviews available

  • Another great entry with good app improvements Dec 14, 2020

    By Jdesurra
    I’ve been a big fan of the Cracking the Cryptic apps, and this one is the best iteration so far. The author line up is great with Christopher Seeliger leading off the puzzles. The killer cages are easily visible, and the themes are a good mix of colors. Like the Sandwich Sudoku app, there is a column to show possible combinations in cages for those of us who struggle with mental math. There are 40 puzzles to start, which I think will keep most solvers busy for a bit. The only downside was I was hoping there would be some little killer puzzles, but it doesn’t look like there are any. That’s a bit of a nitpick since that was never really promised, but it would have been fun to see since combo killer-little killers are quite fun. In case case, this is well worth the money. Another great addition to the CtC app collection.
  • Not your average killer sudoku Dec 22, 2020

    By Jtersesk
    Killer sudoku is my favorite sudoku variant, and when I heard Cracking the Cryptic was releasing their own app, I was thrilled. As with their other apps, every single puzzle is hand-crafted and tested, and the creators themselves have written a series of hints for each puzzle that not only help you find the next step if you’re stuck but actually teach you techniques to improve your skills. Every puzzle in this app is absolutely extraordinary. They’ve been constructed by some of the world’s best setters. This is NOT your average killer sudoku. The logic involved is unique and exciting to find. Plus, the app has every feature I could ask for in a sudoku app: double notation, your choice of error-checking options, the ability to highlight and color, undo and redo. And specific to killer, it will add up cage totals for you, and it gives a list of all possible combinations for a given cage, and has a calculator for you to test other combinations. It’s a magnificent app, and well worth the $5. My only real complaint is the occasional typo in the hints, but it hardly mars the overall experience. Also, if there were a way to view the hint and the grid at the same time, that would be helpful.
  • Top Notch May 23, 2021

    By Dave Wooldridge
    I really appreciate all of Cracking the Cryptics sudoku apps, and this is one of my favorites. I enjoy that the puzzles in the beginning teach you the particular logic that you’ll need for more challenging puzzles (like how the first puzzle teaches you to use The Secret). One aspect I really like is the app does a lot of accounting aspects for you, like giving you possible combinations for a given killer cage along with a calculator, plus automatically removing pencil marks that a placed digit interacts with. That is the developers respecting the intelligence of the solver; the challenge is deductions, not getting buried under your pencil marks or petty arithmetic. Top notch app, hats off to the setters who contributed and the development team.
  • Tough but excellent puzzles Jun 5, 2021

    By dsmarley
    A great app for when I’m looking for a really tough puzzle to chew on for an hour. One of the few puzzle apps where I don’t feel too guilty about resorting to a hint now and then. Or if eight or nine minutes go by and I can’t find a logical deduction that’ll move me forward, the app makes it possible to make a guess as to a digit in a particular box and see where it leads. I color the box before I make my guess as to its contents, so that if I reach a contradiction, I can quick undo my moves until the color disappears and I’m back where I started. Very handy. Speaking of hints, though, the first hint in puzzle #22 is in error. One suggestion: When one taps on a box, all the other boxes that that box “sees” are shaded. I’d find it helpful if the other boxes within the same cage could shaded in a slightly different color.
  • May 19, 2021

    By Timothy Baize
    The puzzles are gonna be hard. You aren't going to be able to immediately put digits into the grid. I will let you in on a few secrets 1-9 added up equals 45 and you should know about the phistomfel ring. All of these are things I learned from cracking the cryptic youtube channel. Just because this is CtC I know for a fact these puzzles have unique solutions and logical solution paths, no bifurcation necessary. Be patient with the puzzles and don't worry about time.
  • May 24, 2021

    By sampath kumar
    A thoroughly enjoyable puzzle that will be enjoyed by anyone that likes maths based puzzles. Very user friendly software to edit, colour, undo the grid. Like all the apps from the cracking the cryptic group this too is fantastic.
  • Another Killer App - Puzzles do not get better! Dec 16, 2020

    By Zegres
    These are the best Killer Sudoku puzzles you will ever solve. They are not created by an algorithm like so many apps, these are hand crafted by some of the best sudoku setters in the world. Each one takes you on a journey where you discover new tricks and ideas. The interface is great, the hints are very strategic and handmade as well. Just 6 months ago I was not aware of the world of handcrafted Sudoku puzzles. Now, because of the Cracking the Cryptic You Tube channel, I can’t get enough. Keep it up guys!
  • Amazing puzzles Feb 11, 2021

    By vandaronas
    The quality of each and every one of these hand crafted puzzles is superb. I look forward to the next update!
  • Awesome addition to CTC collection Dec 16, 2020

    By sodenver
    Fantastic app! Easy to use and lots of options to customize the gameplay. Puzzles are TOUGH, but each has a set of helpful hints that teach you tricks to learn from.
  • Love it Apr 16, 2021

    By Jonathan Card
    I love everything Cracking the Cryptic puts out. Not only are the puzzles fun to play over and over, but their “hints” are also great at teaching how to be better at the puzzles.
  • Jun 7, 2021

    By Emily Fatima Yunan
    Great puzzles with very informative step by step hints, very worthy purchase. Only issue is it takes up a lot of battery and gets really hot when running. Please make it more efficient if possible, can't imagine why it would be so computationally intensive especially if most of the time it's just waiting for input.
  • Apr 20, 2021

    By Ben Graham
    It's hard. I'm not sure if it's too hard; the people getting this are likely to be more advanced players....but it's still very hard. Having watching a ton of CTC I feel I have a slight advantage, but once again, it's HARD! That does mean there's likely great value in this - the 5th puzzle took me an hour and 20 minutes. Point of for the immediate end screen. I want to see what I've just completed.
  • Nice puzzles, needs cloud sync Apr 19, 2021

    By Odysseus42
    I’m enjoying the difficult puzzles so far! I hope they can add cloud sync feature to the app so I can pick up the game between my iPad and iPhone. The pass phrase system is not very convenient and Apple provides a mechanism for apps to sync. It would be greatly appreciated!
  • Feb 6, 2021

    By Marshall Garey
    Really tough puzzles. There's some really neat logic and it can be fun. But when I get stuck, the hints aren't always very helpful. Sometimes they can be rather cryptic (see what I did there?) and I have no idea how they came to the conclusion they did. They also tend to use run on sentences which can make it harder to understand, and I'm a native English speaker. With the puzzles being so difficult and hints not very helpful sometimes, -1 star. Still a good app.
  • Jan 2, 2021

    By Rachel Samett
    I just completed one puzzle and my major complaint is how small the text is for the killer cage sums. I wish there was a setting to toggle that text size. I know you can click on the cage to see the amount, but it's hard to look at the puzzle as a whole on a phone screen. Besides that, love it!
  • Difficulty curve too steep Jan 5, 2021

    By ConfusedSky
    One thing I’ve liked about the CTC apps is that they generally have a pretty gracious difficulty curve where you slowly get introduced to more concepts relating to the sudoku variant. Consequently, I’ve found it a bit harder to develop an intuition for this one. I felt almost completely lost after the first few. Of course I’m still learning, but I’ve had to view the hints quite a bit. I think for example after you get the 12 cage in puzzle 5 the logic is quite accessible most people would be able to figure it out. However getting that cage is a multi step process where you have to look quite a bit ahead to understand. I definitely don’t think that deserves to be a 3 star puzzle for that reason.
  • Not quite there yet Dec 15, 2020

    By ahhhntz
    I’m sure the quality of these puzzles is excellent, and I look forward to trying them once the app receives a key improvement. Current the corner pencil marks do not display in the same location in various cells depending on whether or not the cell contains a cage total, making it much more difficult to scan the grid and much less satisfying to use the app. I will be happy to update my review and increase my star rating once this is fixed, but at present I cannot recommend the app.
  • Apr 7, 2021

    By Jefferson Rodriguez
    Im not the best sudoku player but after playing this for a while I've definitely gotten a lot better. With that being said I can tell when hints are wrong, usually typos of some kind that just make no sense but there are times when I know the logic doesn't add up. I'm stuck on puzzle 22 because the first hint doesn't help and I just don't know where to go from there. There have been some others before but I've ignored them and eventually worked out the solution but I now the hint isn't helping.
  • Jun 2, 2021

    By Krzysztof Przybylski
    For this difficulty you really need to polish your clues so they are clear and **without mistakes**. Oh and all Phistomefel puzzle should be ramped up to 10 ⭐ difficulty. Otherwise it's a delightfully difficult puzzle app with some delicious logic
  • Apr 14, 2021

    By Andy Barnard
    Only 40 killer sudoku puzzles here ranging from easy to impossible. All have hints and tips. Many more puzzle of varying difficulties would make this paid for app much much better even if they didn't include any hints.
  • Dec 23, 2020

    By Mark Holden
    Good puzzles let down by readability of the grid. While I don't doubt the quality of the puzzles, the readability of the grid is a much higher challenge for me. The size of the characters used for cage totals is too small for me to see clearly regardless of the brightness or colour scheme. The higher contrast schemes wash out the grid lines to make them invisible. Turning up the brightness of the screen helps somewhat but that causes eye strain which means I can only play for a few minutes
  • Feb 4, 2021

    By Andy Bryan
    Some of the hints are wrong or very hard to understand. In particular #22 Hint 1...doesnt seem to make sense to me. Still no idea why all the puzzles aren't in app rather than several. Each type could be an expansion pack then. Agree with other reviewers... Balance between fun and difficulty is not quite there. All puzzles should be open from start... Found some that were mega difficult early on and some that were far easier later.
  • Feb 1, 2021

    By Diamond Dustin
    This app fails in the balance of fun and difficult, to go further, the Phistomefel puzzles are not fun. Because you have to unlock puzzles, there are points where you're stuck with a couple puzzles that feel like the setter is just trying to prove how much better at sudoku they are than you. Eventually I'll just start jamming in random numbers until the cell indicates it's correct, and finish the puzzle that way, just so I can hopefully move on to a fun one.
  • Mar 29, 2021

    By Jeroen van den Broek
    Even the supposedly easiest puzzles are way harder than the easiest puzzles in the other CTC apps and in this app the hints are even worse than in the other apps. If you get stuck, forget looking at the hints to help you out. Half the time they mention a wrong row or column number and most of the time there are steps in the logic that aren't easy to see that are completely skipped in the hints. All of the other apps are nice but I can't recommend this one for anyone who's new to killer sudoku.
  • Apr 23, 2021

    By Ryan Harvey
    The puzzles are terribly designed for use on a phone. Most require summing pen and paper or a switching back and forth between a calculator and the app. I shouldn't have to be solving systems of equations to complete a puzzle that is designed to work on the phone which is exactly what the hints say to do. Loved the original app. This is tedious and takes the fun out of solving the puzzles.
  • Dec 29, 2020

    By Mattias Sossna
    This one is way harder then the others (and several of the tips have mistakes in them), I also found a lot of the pussel to be really boring (some are really good on the other hand) and not to the standards of previous titles... Sadly you're forced to play the bad puzzles to continue... Killer Sudoku is my favorite sudoku variant so really disappointing in this app....
  • Game#2 has bad cages that can’t be solved Jan 27, 2021

    By Tolator
    Lower left square has 3 cages with one space left and yet the total is already 45. So can’t solve puzzle 2, which is required to get enough stars to move to puzzle 3. Checked for updates to fix problem but none available.

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