16 rooms on a side
Sixteen is the Hard preset under fog. Classic shows everything; fog turns the same walls into memory.
Sixteen rooms under the lamp is where many players first lose the map. Tap only walks revealed tiles — swipe or arrows when the corridor is dark. Same seed in classic is a fair practice board.
The number is rooms, not pixels. Walls sit between rooms, so the drawing is 33 tiles across. Start is top-left; exit is bottom-right. Same seed, size, and mode rebuild the same corridors.
How to walk it
Arrows and swipe take a whole corridor and stop at the next fork. Yellow marks where you moved — not a solved path. Hint draws one solid arrow; Peek flashes the shortest route. Either leaves that run off local Marks.
Also: all room counts, make desk, print this size, right-hand rule.