FLOW - this game is very cool. Based in Flash, you control some sort of glowing organism in an ocean of other living organisms of different shapes and sizes. The aim of the game (I assume) is to eat up the other floating organisms to grow your own creature. Eat the red creature to go lower in depth, blue to go higher. The lower you go, the bigger (and more dangerous!) other organisms are. Hold your left mouse button to swim faster.
The graphics are wondrous, the animations are fluid, even the music is engaging! To top it all off, enemy organisms have a little personality to them, they glow white when they feel neutral, orange when they become agressive, and blue when they become frightened of you.
Very fun and a great time-killer. Enjoy!