I can't remember now where I came across this strange little web game/toy: Grow Cube. Basically, you play by selecting objects to place on a cube. Depending on what other objects are present, objects will "level up", meaning that they change and grow, and sometimes interact with other objects, all with cute little animations. It's sort of a logic puzzle - as you play, you start to figure out that certain combinations of objects will produce particular results. I haven't really tried to figure it out in any kind of systematic way yet - I'm just having fun seeing what happens.

There are a few other games on the site using essentially the same concept, including one with a cute RPG theme, where you get to see your hero battle the bad guys on the landscape you've created at the end of the game. Very nifty. Check it out.