Break
Twenty seconds, one square, your reflexes
Hit the lit square before it goes dark. It gets faster. A miss costs you a point.
Why this page exists
Because a website does not have to be boring, and because everything you just used — the grid, the timer, the score — was written by hand for this page. Nothing installed, nothing bought. It is exactly the method applied to serious projects.
Share your score, or send the page to someone faster than you.