It's been a long time since such a unique game was released...
The sheer amount of tools, objects, decorations, and materials presents the level creation aspect of the game in an astounding way. The fact that there is no limit to the amount of creativity you can put into these maps creates endless possibilities for levels and challenges that you can play. Basically, the game is bottomless in its playability.
The pre-made editor levels that create the story line of the game are fun, engaging, and wonderfully crafted as well as themed. They may not be the most difficult levels to ever be created into the platforming world but the fun factor as well as the aesthetically pleasing environments more than make up for a lack of difficulty.
The greatest strength of the game is, obviously, the community based, online, level sharing available through the Playstation Network. It is also, however, the game's only weakness. Considering that if, for whatever reason, a player doesn't have online on their PS3 then they can only experience the editor levels which, although they are fun, are sometimes not comparable to some of the well done player levels.
The game presents itself in an incredibly fun manner with a very finely crafted formula of creativity and challenge. This game is, in fact, the reason that I purchased my PS3.
If you happen to be a fan of having fun for the sake of having fun, without the level grinding, the ammo collecting, and the linear game play, then this game is for you. I highly recommend this one!