2-Player Reaction Test
One screen, two players, one winner. Player one owns the left, player two the right (or use A and L on a keyboard). When the screen turns green, smash your side first. Go before green and you hand the round to your opponent. First to three wins.
Ready?
Both players tap your side to begin.
The purest competition there is
Strip a contest down far enough and you get this: two people, the same signal, and whoever's body moves first. No skill tree, no gear advantage, nowhere to hide. It is the same thing happening on an F1 grid or a sprint blocks (a shared start and a fight over milliseconds), just with your thumbs instead of a thousand horsepower.
What makes it fun in person is the nerve. As the green gets closer the temptation to jump grows, and the player who cracks first loses the round outright. Holding your nerve while staying loose enough to fire is the whole game, and it is exactly the skill the solo reaction game trains under pressure.