Goal

A grid of cells shares one colour — except one cell is slightly different. Find it and tap it. Find as many as you can in 60 seconds.

Levels

Finds move you up: the grid grows from 3×3 to 11×11 and the difference gets subtler. Levels 1–4 take one find each; from level 5 it takes two finds to move up — reaching level 10 in a minute is a great game. A wrong tap costs 2 seconds; after two, the odd cell is revealed — tap it for a fresh grid at the same level (no points).

Scoring

Each find earns 4 + 2 × the level. Find several in a row without a wrong tap to build a streak.

Tips

• Relax your eyes and use peripheral vision rather than examining cells one by one.
• Let the odd cell pop naturally — forcing it rarely works.
• On large grids, divide into quadrants and check each zone.

Visual Discrimination

Detecting subtle colour differences sharpens perceptual sensitivity — training the visual cortex to distinguish fine gradations that most people miss.

Selective Attention

Filtering through a field of identical items to find the single outlier exercises the brain's ability to suppress irrelevant information.