Duel

A duel strips a game back to the only thing that matters - you, one opponent, and whichever of you gets it right first. There's nowhere to hide in a format that small.

Cowboys Duel is the purest version, a reaction test dressed as a standoff where drawing early is as fatal as drawing late. Football Duel reduces a whole sport down to a single repeated contest. Escape School Duel turns an escape into a race against someone rather than a puzzle you solve alone, which changes how much risk is worth taking. Every one of them is over quickly enough that you'll want a rematch before you've finished thinking about the last one.

There are 3 free games under this tag, all playable in the browser with nothing to install, and every one of them is over quickly enough to demand a rematch.

The two-player shelf is 2 Player games, and Competitive Games collects everything with someone to beat.