Here is a genuinely strange fact about your excellent brain: interrupt its view for a third of a second and it can lose track of enormous changes, a vanished object, a colour swap, a picture that moved a hand-width. Psychologists call it change blindness and have been delighting in it since the nineties. AGAIN is that phenomenon with a cosy room, a polite blink, and a score.
Why it exists
Change blindness is the mind's real and slightly embarrassing inability to notice large changes across an interruption. Show a person a room, blink it, move a chair, and most people will swear the room is the same. This toy is that experiment made cosy. You get a few seconds with a little room, the room blinks, one thing is different, and you tap what changed.
One thing
Every room is seeded, and one object differs between before and after. The toy can name it, so you are never hunting a change that is not there. When you miss, the miss is yours. That is the phenomenon.
The look gets shorter
Rounds shorten the time you get with the room and make the change more subtle: a colour a shade off, a thing that moved a little, a thing that left. The streak is the score, and how far it goes says something about how your eyes take a room in.
Three misses
Three wrong taps and the room keeps its secret. You can start again at once, and the toy remembers your best streak for next time.
The quiet parts
No account, no ads, nothing leaves your browser. Nothing in this room measures, diagnoses, or knows anything about you; it is a toy about how minds wobble, made with affection for the wobble.