Keydoku: The Daily Detective Sudoku

Field notes

Keydoku builds its deduction system from several kinds of spatial evidence: named zones, row and column separation, blocked furniture, and truthful suspect statements. The homepage’s example uses three suspects and three zones, with pencil marks, contradiction checking, undo, and a hint that recharges every three minutes. Its longer structure is described as 50 cases across five settings, alongside an endless mode and a daily archive.