Slap The Rat is a quick reaction game: a rat appears, you hit it, and the next one shows up somewhere else a little faster. That is the entire loop, and it is enough.
Games built on one input live or die on how fair the timing feels, and this one gives you just enough warning to react without ever letting you settle into a rhythm. Score is the only progression, so a run ends when your reactions do.
It plays with a single click or tap, which makes it work as well on a phone as on a desktop. Runs in the browser with nothing to install and no account. A round takes well under a minute.