Comparison

Sum Fun vs Killer Sudoku

Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.

Head to head
About

Sum Fun

A unique number puzzle game that combines logic, numbers, and strategy. Enjoy endlessly replayable puzzles with creative board shapes and a brain-boosting gameplay experience. Play at your own pace with no time limits and challenge friends.

Highlights
  • Unique number puzzle gameplay
  • Variety of creative board shapes
  • Brain-boosting mental workout
  • No time limits for relaxed play
  • Challenge friends offline
  • Easy to play, fun to master
Features
Read full description

Sum Fun – The Number Puzzle Game for Sharp Minds Place numbers, match sums, blast the board! Sum Fun is the unique number puzzle that's been loved by players worldwide since 2015. How To Play (3 simple rules): 1. Place a number into any empty slot 2. If it matches the last digit of the sum of its neighbours, they get blasted away! 3. No matches? Place a number that sets up a future sum, and keep blasting until the board is empty! Why you'll love Sum Fun: • Easy to play, fun to master – just 3 simple rules, with surprising depth and strategy • 20+ creative board shapes – play on a Hexagon, Pyramid, Star, Heart, Turtle, Rocket, Butterfly, Snowflake, and many more, with new shapes added regularly! • Seasonal Postcard Challenges – play limited-time events and collect unique downloadable artwork (by real artists!) • No time limits – play at your own pace and relax while keeping your mind sharp • Challenge friends (and yourself!) – share puzzles via QR code, text code, or pass-and-play. No internet needed! • No annoying pop-up ads – your concentration stays on the puzzle, where it belongs! We play Sum Fun too, and keep the experience friendly. • Brain-boosting gameplay – after a few games, you'll be adding up numbers faster than you can say, 'What's six plus eight?' • Multiple themes – choose from Light, Dark, and Midnight to suit your style If you enjoy Sudoku, Kakuro, or other number-based brain games, you'll love the unique twist of Sum Fun. Exercise your mind, master the numbers, and discover why players keep coming back – download free today!

About

Killer Sudoku

Engage your mind with a logic-based number puzzle game. Place digits 1-9 into grids, ensuring each appears once per row, column, and mini-grid. Enjoy daily challenges, customizable themes, and intelligent hints for a brain-boosting experience.

Highlights
  • Multiple difficulty levels
  • Daily challenges and trophies
  • Pencil mode for notes
  • Highlight duplicate numbers
  • Intelligent hint system
  • Customizable themes
  • Unlimited undo/redo
Features
Read full description

Sudoku Free Puzzle Game is a welcomed and addictive Brain Sudoku puzzle game on App Store. You can download Sudoku free app for your iPhone. You get 5000+ challenging Sudoku puzzles everyday to one true solution. Killer Sudoku the best puzzle game for your brain, logical thinking, memory, and A GOOD TIME KILLER! Killer Sudoku is a logic-based number puzzle game and the goal is to place 1 to 9 digit numbers into each grid cell so that each number can only appear once in each row, each column and each mini-grid. With our Sudoku puzzle app, you can not only enjoy sudoku games anytime anywhere, but also learn Sudoku techniques from it. Key Features 1. Sudoku puzzles come in 4 difficulty levels - easy Sudoku, medium Sudoku, hard Sudoku and expert Sudoku! Perfect for Sudoku beginners and advanced players! 2. Daily Challenges - Complete Daily Challenges and collect trophies. 3. Pencil Mode - Turn on / off pencil mode as you like. 4. Highlight Duplicates - to avoid repeating numbers in a row, column and block. 5. Intelligent Hints - guide you through the numbers when you get stuck 6. Themes - Choose the theme that makes it easier for your eyes. 7. Long press to fill quickly On this Brain Sudoku free app, you are also able to 1. Turn on / off sound effects 2. Turn on / off Highlight identical numbers 3. Auto remove notes from all columns, rows and blocks once the number is placed 4. Unlimited undo & redo 5. Auto-save-Pause the game and resume the game without losing any progress 6. Sudoku online & Sudoku offline You may also find the following Brain Sudoku features useful 1. You can share to your friends via Google+, Facebook, Twitter etc.. 2. Use dark mode to protect your eyes 3. Turn on / off timer when you play the sudoku puzzle 4. 100 new sudoku puzzles every week. 5. New types of Sudoku puzzles, like Killer sudoku, letter Sudoku, will be available. 6. Good gameplay 7. Intuitive interface 8. Easy tools, easy control 9. Clear layout Our free Sudoku puzzle app has intuitive interface, easy control, clear layout and well balanced difficulty levels for beginners and advanced players. It’s not only a good time killer but also helps you think, makes you more logical and have better memory. When you first open our Sudoku app, you see a guide tour teaching you how to play Sudoku and when you open the puzzle game app for the 100th time, you can see yourself a Sudoku master and a great Sudoku solver. You’d be able to play any web sudoku fast. Come to our Kingdom of Sudoku and keep your mind sharp. If you have any idea for our Sudoku puzzle game app, or if you have any question about Sudoku and you want to discuss with us, please send us emails at support@oakevergames.com. We are always here for you. Privacy Policy: https://oakevergames.com/pp.html Terms of Service: https://oakevergames.com/tos.html EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula

Screenshots

Sum Fun4 screens
Killer Sudoku4 screens

Verdict

The call

The clearest difference is review sentiment: Sum Fun at 100% against Killer Sudoku's 39%. Sum Fun also leads on in-app purchases (none vs 6) and rating (4.9 vs 4.7). Killer Sudoku's advantage is ratings volume (27K vs 33). On price, update cadence, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Killer Sudoku sells 6 in-app purchases, starting at $1.99 per 7 days. Sum Fun asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Sum Fun holds the better App Store score, 4.9 against 4.7. That said, the two scores are not equally well evidenced: Killer Sudoku has 27K ratings behind it against 33, so its average is the more settled of the two. Written reviews point the same way: 100% of Sum Fun's written reviews are positive against 39% of Killer Sudoku's.

UpkeepUpdate frequency

Sum Fun ships an update every 10 days, Killer Sudoku weekly. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
Sum Fun versus Killer Sudoku: the parameters behind the verdict, then further details
ParameterSum FunKiller Sudoku
PriceFreeFree
Rating4.9 (33 ratings) — better4.7 (27K ratings)
Positive reviews100.0% of reviews — better39.1% of reviews
Number of ratings3327K — better
Update frequencyEvery 10 daysWeekly — better
AdsYesYes
In-app purchasesNo — betterYes
MonetizationAd-supported — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size181 MB253 MB
Age rating4+4+
DeveloperGreg SharpeOakever Games

Customer experience

Sum Fun

All ratings33 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews47 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Killer Sudoku

All ratings26,616 ratings
Positive92.6%
Neutral5.0%
Negative2.4%
Written reviews386 reviews
Positive39.1%
Neutral14.8%
Negative46.1%

Bugs and requests

Sum Fun

Not enough reviews yet to summarise bugs or requests.

Killer Sudoku

Reported bugs

5 issues
  • Game freezing and crashing
  • Ads causing issues and preventing gameplay
  • Losing progress and data after updates
  • Numbers not showing up in puzzles
  • Battle mode bugs and glitches

Requested features

5 requests
  • Option to turn off timer
  • More note-taking options
  • Ability to choose difficulty level for daily challenges
  • Bring back seasonal challenges
  • Improve battle mode matchmaking and ad issues

In-app purchases

None

Sum Fun

No in-app purchases

6 purchases

Killer Sudoku

Subscriptions3
  • Sudoku Weekly Subscription$1.997 Days
  • Sudoku Monthly Subscription$4.991 Month
  • Sudoku Yearly Subscription$15.991 Year
One-time3
  • Battle Tickets *30$0.99
  • Battle Tickets *100$1.99
  • Battle Tickets *200$2.99

Questions

Is Sum Fun free?
Sum Fun is free to download, with no in-app purchases.
Is Killer Sudoku free?
Killer Sudoku is free to download, with in-app purchases available.
Which has better reviews, Sum Fun or Killer Sudoku?
Sum Fun is rated higher. Sum Fun averages 4.9 out of 5 from 33 ratings, while Killer Sudoku averages 4.7 from 27K ratings.
Do Sum Fun or Killer Sudoku have ads?
Both Sum Fun and Killer Sudoku show ads.
Which is updated more often, Sum Fun or Killer Sudoku?
Sum Fun ships an update every 10 days, and Killer Sudoku weekly. Most recently, Sum Fun was updated on October 23, 2026 and Killer Sudoku on October 24, 2026.

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