12 × 12 turns Hitori into a long-form solve. Duplicate groups interleave across many lines at once, and the board rewards players who track the shading cascade methodically instead of hunting cell by cell.
On boards this size the player tools matter: use the shade/mark input toggle to paint confidently, and lean on the error highlighting to catch an illegal adjacency before it derails ten minutes of work.
Warm up on a 9 × 9 if the jump feels steep, or browse every size.