Originally an avoidance game, you play as a rectangle that can fly around and crash into the ground. Arrow keys to fly around, press and hold space to crash into the ground, and p to pause. This might crash your browser, so save anything important.
Chu Chu Rocket
This is a clone of SEGA's game Chu Chu Rocket, originally for the Game Boy advance and Dreamcast. This is a puzzle game, your goal is to use arrows to get all of the mice to the goal while avoiding cats and pits. Again, this might crash your browser, so save anything important.