Here’s a really clever little game: Poom. A ball drops down from the ceiling, and you control a little grid of flat squares with your mouse below it. Your goal is to move the grid around so that you bounce the ball; if you accidentally move an empty part of the grid beneath the ball, it falls down and you lose. Sounds easy! Except every time the ball bounces, the grid changes … giving you barely a millisecond to quickly figure out where to shift it to next.

The gameplay here is so unusual and new that it’s kind of hard to explain. Just go play it! But give yourself a half hour, because it’s seriously addictive.