The Hamiltonian Circuit vs Sumaddle Usage & Stats
Find a path that visits every square in the grid, avoiding walls and never crossing itself, to create one continuous circuit.
To get the hang of things, start with one of the simple 4x4 grids. Plot your moves carefully. Try to think ahead; not just by one square, but by four or five. If you think you've made a mistake, trace back over your line. It will disappear.
If you really get stuck, press Hints. Any mistakes will turn red, then disappear. But if you're on the right path, we'll add a line.
There's only one solution for every puzzle. When you find it, you'll know.
Puzzles start with 4x4 grids and go all the way to 20x20. The bigger puzzles are very challenging and can take hours to solve. If you have to quit in the middle of one, don't worry: your progress is automatically saved.
Many find working on these circuits meditative; others reach for the ibuprofen. But no matter which camp you find yourself in, know you're exercising your abstract thinking skills and challenging your brain in ways that actually matter.
Inspired by a puzzle created by Irish mathematician William Rowan Hamilton in 1856, these circuits start off easy and get hard. Really hard. Good luck!
Terms of use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
- Apple App Store
- Free
- Games
Store Rank
- -
• “Brilliant puzzle game”, UK App Store review Apr 2025
• “Best Puzzle Game I’ve Ever Played”, US App Store review Jan 2025
• “The ONLY iOS game I've never gotten tired of”, Reddit review Apr 2024
This type of logical puzzle was first seen in the Japan Puzzle Championship 2006 and is sometimes known as Doppelblock, or Smashed Sums. When played with pencil and paper, these puzzles can be hard work to solve. Sumaddle changes that by adding the essential element of interaction. This transforms the puzzles into intriguing brain teasers that unfold before your eyes.
Each puzzle has a unique solution. Finding the solution involves fitting the number combinations to the clues. The app makes it easy to view the possible combinations, you don’t need to do any sums in your head. Instead, you can focus on using logic to narrow down the combinations and find a fitting arrangement.
Some reasons why you will enjoy playing Sumaddle:
• puzzles range in size and difficulty from small and simple to large and mind-blowing
• more than 120 puzzles are included for free
• all puzzles can be solved with pure logic, no mental arithmetic required
• the sophisticated built-in help can explain the logical reasoning at each step and also fix mistakes if you go wrong
• the built-in help is completely free, use it as much as you like
• works offline (great for long journeys)
• a high standard of accessibility, including comprehensive support for VoiceOver
• ad-free play - there are absolutely no ads!
- Apple App Store
- Free
- Games
Store Rank
- -
The Hamiltonian Circuit VS. 
SumaddleJanuary 13, 2026