I just finished Katamari Damacy on the PS2 [English link] which a friend [LH] lent me a month or two ago. It’s a great little game, and since it’s been out a while, you might be able to pick it up cheap. Basically, you roll a ball around a home, then town, then country then world, picking up objects, which as your ball gets bigger, means you can pick up bigger objects. On each level, you have to achieve a certain size in a set time, or pick up a certain number of types of objects to complete the level.
The game itself is made in a very funky style with great tunes, weird sound effects, and a bizarre cartoon story between each level. It’s definitely a game you can burn a few hours away with on a rainy afternoon. Though not a very long game in itself, it as a lot of fun to go from rolling small erasers and such on the first level, to rolling Fuji-san and Godzilla in the last level to make a new moon.