The Wonderful End of the World is, in short, a PC clone of Katamari Damacy, so it is easy to just say if you like that style of game you will like this one, but there are some querks you should know going in.
The idea of the game is simple, you play this walking man made of magnetic balls that when you get near objects of your size or smaller you pull them into you, letting them become a part of your body and making you grow, you keep growing bigger and bigger and your objective is to reach a set score before the timer runs out, this is the main game mode, once you beat all twelve levels you unlock endless modes and whatnot, letting you goof around.
This concept is fine and the game itself is fun but there are some mixed feelings I have for it, to start the sound design leaves much to be desired, basicly every item you pick up makes the same sound save for a telephone or something of that nature, all the sounds in game were obviously done on the cheap with what sounds like people making noises with their mouths, but that is not entirely a bad thing and has some charm to it as well.
The music is very well done and as with most Dejobaan games the overall design of the game is well put together, comical and tight, though there are issues that can be nitpicked, the controls are at times quite loose, it is not a very hard game or long either, you can beat the whole game in one sitting (In fact there is an achevement for doing that) and though the levels are very well made with unique art designs, there is very little replay value.
It is impossible to not compare this game to Katamari, but if you do so you will find that Wonderful falls a bit short from reaching that charming and very japanese series of games, however dispite that I still recommend this game, it's a fun time waster, doesn't cost a lot, and has just enough charm in it to get by, not to mention that if you are a fan of Katamari you have very few options on the PC for games like it.