Well, I finished Psychonauts, and I have to say that it's one of the best video games I've ever played. It's certainly up there with Planescape: Torment, Star Control 2, and Baldur's Gate 2.
Like all the best games (and fiction, for that matter), Psychonauts is all about story, character, and imagination. You take on the role of Razputin, a boy who ran away from the circus because he wanted to attend the Whispering Wood Psychic Summer Camp and become a Psychonaut (basically a mentalist super agent).
Though Raz is a standout student from the start, all is not well at Whispering Wood. The camp is built on the site of an ancient metorite impact that infused the area with "psitanium" -- an element that has strange effects on psychic powers and on the region's wildlife. But that much, at least, is well-known to the staff of the camp.
Less well known is the fact that a mysterious creature haunts nearby Lake Oblongata and the surrounding woods. Mysterious things start happening in the camp, accompanied by strange dreams heavily involving meat products.
It's kind of hard to describe without giving a lot away.
It suffices to say, however, that Raz is in for a hell of an adventure, both in the real world and, later, within the minds of half a dozen or more people, each of whom has serious issues.
It's within these minds that the game's incredible imagination really stands out. Each mental world is totally unique, with its own hazards, sights, and meaning, and all of it is infused with a fantastically weird sense of humor.
The brains behind Psychonauts belong to Tim Schafer, whose previous endeavors include Day of the Tentacle, Grim Fandango, and Full Throttle (all for LucasArts). I've only played Full Throttle, but I know that the mention of Grim Fandango is enough to make people who played it sit up and take notice.
Gameplay-wise, it's pretty solid. The only real issue is the learning curve, which has a couple of very irritating spikes in an otherwise mellow field. I've heard the last few levels described as "like childbirth, only more painful," but, hell, if I managed to finish it, it can't be that tough. However, I understand that the PS2 port of the game was very sketchy, control-wise, making the difficult parts particularly frustrating. The PC version is tough, but certainly doable.
Though the game came out in 2005, it's still available through Steam on the PC side (and for only $20). The title is officially "out of print," however, so finding it for a console (or finding a hard copy for those who despise Steam) may be a bit difficult.
It's certainly worth it, though. I actually watched the entire credit roll and then downloaded the BINK video player just so I could watch a lot of the cutscenes again after finishing the game.