If you like Sudoku, the useful question is not simply “what other puzzle uses a grid?” It is which part of Sudoku do you want more of? Some alternatives keep number placement, some add arithmetic, some remove numbers entirely, and some turn a solo solve into a shared daily or live event.
Seven Sudoku alternatives worth knowing
If you like Sudoku's candidate elimination
Futoshiki, KenKen, Calcudoku and PUZRU are the closest choices in this list for players who enjoy narrowing legal digits cell by cell. Kakuro leans more heavily into sum combinations, while Killer Sudoku keeps the familiar 9×9 Sudoku structure and adds cage arithmetic.
If you want a shorter number puzzle
A 6×6 format reduces visual scanning without removing row-and-column interaction. PUZRU keeps six candidates, adds connected sum cages, and verifies production puzzles for one exact solution and a logical no-guess path.
If you want something genuinely different
Nonograms move away from number placement entirely: the clues describe runs of filled cells that reveal a picture. That makes them a better alternative when the part you want to change is the Sudoku-style digit grid itself.
Where PUZRU fits
PUZRU is an independent puzzle format. It combines Latin-square placement and addition cages on a fixed 6×6 board, then adds product modes most pencil-and-paper puzzles do not have: a deterministic Daily, a permanent completed-puzzle Archive, a progressive Training Room and one global live puzzle where the first verified correct solve becomes Discoverer.
Put the idea into practice
The fastest way to understand the interaction between row, column and cage constraints is to solve a board. Start in the 200-puzzle progressive Training Room, then enter the live world whenever you are ready to race for Discoverer.