Suprisingly addictive! You need to a goal or something to gauge success with tho. As it stands it's more of a toy than a game. A timer that resets on failure would already suffice.
This shows a lot of potential! I expecially enjoyed watching all the critters move around. Have you thought about making smaller levels? Having a single level is good for the atmosphere of the game, but creating multiple levels with new challenges helps alot in finding the juicy core of a game.
