Sudoku meets Picross, on a hex grid.

HexLemma is a constraint-satisfaction deduction puzzle played on a hexagonal board. Each cell holds a hidden value from 1 to 7. Your job is to deduce every one — guided by six clue families that compose into intricate proofs.

You never guess. Wrong moves are blocked before they can land. Every commit you make is provably correct, every elimination provably necessary. The puzzle is fair, and the proof is yours alone.

The six clue families

• Pair-Same (=) — two distant cells share a value.

• Pair-Differ (≠) — two distant cells must differ.

• Order (<, >) — one cell's value is smaller than its partner's.

• Count (N·V) — exactly N of a cell's six neighbors hold value V.

• Parity (E / O) — the cell holds an even or odd value.

• Vertex Sum (Σ) — three cells meeting at a corner sum to a target number.

The clues compose. A Count tells you where 3s can land; a Pair-Differ narrows it further; a Vertex Sum rules out the last ambiguity. Every solve is an emergent chain you build, not a recipe you follow.

Three ways to play

• Campaign — 25 hand-tuned puzzles across five stages. Each stage introduces one new clue family. Start with the basics in Stage 1 (Foundations); finish on full-grammar Insane boards in Stage 5 (Capstone).

• Daily Challenge — one puzzle per UTC date, the same for every player worldwide. Compete on the Steam leaderboard.

• Random Puzzle — pick a board shape, difficulty, and seed. Eight board shapes (Hex Disk, Rectangle, Triangle, Parallelogram, Hex Star, L-Shape, Donut, organic blobs). Four difficulties from Easy to Insane.

Built for sitting with

• No timer. No mistake cap. Take five minutes or take an hour.

• Cloud saves across machines.

• Move replays for every puzzle you finish.

• 13 achievements across campaign progress, perfectionist runs, and daily streaks.

Coming Soon

• Localization: English, German, French, Italian, Spanish, Polish, Finnish, Norwegian, Swedish, Turkish, Portuguese (Portugal + Brazil).

• Themes: Four themes including two designed for colorblind players (deuteranopia + tritanopia).

• Full controller support with hex-natural six-way cursor navigation. Steam Deck ready. Partial support already baked. Working on control scheme optimizations.

A relaxation puzzle with teeth. Settle in.