One Square: Spot the Odd One

Find the one square that is different from the rest. There are six kinds of difference: Color — its color is slightly different Move — it moves slightly differently Shape — its shape is slightly different Pattern — its pattern is slightly different Blur — its outline is slightly more or less sharp Timing — it changes once, then changes back Anyone can solve level 1. By level 100 you can barely tell them apart. For color, the difference (ΔE2000) shrinks from about 9 to 0.8 — quietly, one puzzle at a time. ■ See what was different After each answer, the two squares are shown side by side with the exact difference. For color, which of red, green or blue moved; for motion, how much the range differed. The ones you missed are the most surprising. ■ Same SEED, same 100 puzzles A SEED is a short code like "C-8K4M2P". Share it, and anyone on any device gets the same 100 puzzles in the same order. Race a friend on exactly the same puzzles. ■ Sight Your best level is recorded for each of the six kinds and shown on a radar chart, so you can see which differences you are good at — and which you are not. ■ How to play Three plays a day, 100 puzzles each. Once you have gone far enough, you can start from half of your best level. You have three skips per play. Miss after using them all, and the run ends. No sound. No notifications. Ads appear only if you choose to watch one for an extra play.