crossums
pre-orderfill every cell so its row and column add up. scratches the sudoku itch with a mechanic all its own.
// how it works
each row and column shows a target sum. fill in the blanks with digits 1–9 so every row and column adds up — satisfied sums turn green. duplicate digits are allowed, and there's no uniqueness rule to fight: any arrangement that hits the sums counts as correct. this one is the game's real puzzle 001. go ahead.
// what's inside
200 hand-verified puzzles
every puzzle is generated, checked for a real logical solving path, then i play it through by hand before it ships — no guessing required. two more volumes available separately.
three grid sizes
3×3 through 5×5, introduced gradually as difficulty ramps across five chapters per volume.
quiet by design
no ads, no streak guilt, no dark patterns. no attempt limit — solve it first try for the top mark, or take your time. always forward progress.
// if you love it, there's more
volume 2 · regions
another 200 hand-verified puzzles. adds region constraints — bordered groups of cells that must sum correctly alongside their row and column. same rules, a new shape to reason about.
volume 3 · crossings
another 200 hand-verified puzzles. regions can now overlap, so a single cell can count toward two sums at once. same difficulty, a new twist to reason about.
// privacy at a glance
full policy →crash reports only, never linked to your identity.
no third-party trackers or ad SDKs.
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