Super Liquid Soccer is football played by characters made of something between rubber and water. The physics are deliberately unstable: your player flops, overbalances and skids, and scoring is as much about wrestling the wobble as about aiming. Matches are short, goals are ridiculous, and nobody has ever executed a planned move in it.
It plays best with two people on one keyboard, where the flailing becomes a shared joke rather than a frustration. Against the computer it is a decent one-minute distraction; against a friend it is one of the funniest games on the site.
Yes — two players share one keyboard, which is how it is meant to be played. A single-player mode against the computer is also available.
The physics are intentionally soft-bodied — characters behave like liquid-filled bags rather than rigid figures. The unpredictability is the game.
It runs in the browser with nothing to install, so it works on a school Chromebook wherever the site itself loads.