Pretty fun...
You play as Jim Hawkins, a troubled, misguided teen, who is in trouble with the law. Your mother, who is worried about your future, speaks to her intelligent friend about it, and he says that it'd help Jim if he came on an expedition with him, and Jim stumbles on an artefact. He fiddles with it, and it makes a map which leads to Treasure Planet. The game is simple, you go around completing objectives for the level, which activates beacons. These guide you to Treasure Planet, and if memory serves, there are about six in each level. Jim has the basic platformer moves. Kick, double jump, punch, simple stuff. Jim's big hitch is that a little pink floaty thing called Morph can attatch itself to Jim, and form all sorts of stuff, from a pair of oversized mechanical gloves, to a helping hand which can push and pull levers that you can't. These only last for a short time though, and the time is only long enough so you can just get there, and if you miss it (which you will), you'll be cursing at your TV until you get it.
The other big section of the game, is Jim's Solar Surfer. These levels play like the others, in that you go around, activating beacons by completing objectives, except you race around on a Solar Surfer instead. You can do tricks featured in the movie, which is fairly fun once you figure out the combinations. Again, there are times when you may die a cheap death (AND YOU WILL), which will have you cursing at the TV. The Solar Surfer levels occur at just the right times when your about to get sick of the running, kicking, and Morphing.
The graphics are... alright. You will see many of the same enemies (as per usual for a Disney game), and you will see the same scenery about a thousand times over in each chapter, which are split into about three levels each. The music is just annoying. It is the stereotypical pirate music, except when you're on the Solar Surfer, which has it's own little annoying tune. My suggestion is grab your iPod, and listen to an awesome song while you play. Another bad thing, is that the game is too easy, but then there are some insane objectives which are easy, but are just too fiddly and annoying to complete, as you be sick of it after about two tries.
Overall, Treasure Planet is a fun title in the Disney lirbary, and if you overlook the flaws, there's a genuinley fun game to be found.