The Wonderful End of the World is a essentially a Katamari Damacy imitator for the casual PC market. Instead of being a tarball, you're a biped, walking with the arrow keys and optionally turning with the mouse, and as in Katamari, things you walk into adhere to you, increasing your size and ultimately allowing you to pick up larger things.
As befits something sold into the casual market, it's a lot easier; you get a letter grade at the end of each level, and anything over a B (which isn't hard to get) opens up new levels; no humiliating chastisement from the King. The UI isn't as physically satisfying as the dual-joystick controls of Katamari, but then, PCs don't have dual joysticks, and it's workable. The fact that it's easier isn't all bad, either; its a game you can pick up and play for a few minutes of goofball enjoyment, without having to endure the tenseness of Katamari's countdown.
The musical score is excellent, peppy, REM-like rock, the graphics clean and brightly lit, and the levels are well conceived. You're not going to throw away your Katamari discs, but World is an interesting variation and a nice change of pace -- and of course you can play it on your PC.