Japsum vs Slitherlink Diamond

Japsum (short for "Japanese Sum") is a free, logic-based, combinatorial number-placement puzzle game. It’s similar to Kakuro or Sudoku puzzles, but with its own unique twist. Starting with an empty grid, you’ll use hints provided on the sides and top to place numbers or black boxes in the grid. The hints indicate the sums of consecutive numbers, with no black boxes in between. Multiple hints mean that sequences of numbers are divided by one or more black boxes. By using logical reasoning and interpreting these hints, you’ll make steady progress in filling in the grid with numbers and black boxes. Be prepared—especially with the larger grids, these puzzles can get very challenging! The app offers grid sizes ranging from 3x3 to 22x22—the largest puzzles of this kind, as far as I know. Every puzzle has exactly one unique solution, ensuring a fair and rewarding challenge. As you solve puzzles, your level increases, unlocking larger grids and fun bear avatars that you can choose to represent your progress. Best of all, Japsum is completely free—so you can dive into the world of Japanese Sum puzzles at no cost. Are you ready to test your logic and take on the ultimate puzzle challenge? Download Japsum today and start solving!

A nice slitherlink puzzle projected on a ball. Make one line. Surround every number on the ball with exactly that amount of thick lines. Is it a challenge? Yes! Can you solve it? Yes you can!