All tiles are grayscale — pure neutral tones with no hue or saturation. One tile has a slightly different lightness. Find it before time runs out.

Without color to guide you, only your sensitivity to light and shadow remains.

Grids grow from 2×2 to 7×7 as you progress. The lightness difference shrinks with every round.

10 seconds per question. Time out = instant game over. 3 wrong taps and it's game over.