Pleasant. Nothing more, nothing less.
"K-PAX" is yet another Kevin Spacey vehicle in the vein of "Usual Suspects" and "American Beauty" in which we spend the majority of the film simply trying to figure out his character.
Unfortunately, this film has far fewer interesting side stories to keep the plot moving when Spacey is off-screen. It's basically the tale of an unknown stranger who, despite a group of non-believers that say he's just another lunatic, changes the way everyone around him thinks. That's right, it's yet another Jesus parable.
The twist is that Spacey's character is sent to mental institution within the first five minutes of the film because he contends he is from the planet K-PAX. Thus, he spends the majority of the film converting skeptics in a mental hospital. Predictably, the patients quickly become disciples of Prot (Spacey) and abide by his words as if they were law.
Prot's biggest skeptic is his psychiatrist (Jeff Bridges). As Bridges tries to understand the puzzle of Prot, his patient attempts to teach Bridges how to better appreciate life. As his character becomes more and more obsessed with figuring out Prot, it becomes increasingly obvious that he should be simply taking Prot's advice rather than trying to figure out whether he's an alien or not.
Had this situation occurred with two lesser actors, the sappy sentimentality factor would have been off the charts. As it is, "K-PAX" still has a healthy dose of mushy drivel, which drags down the movie's ending.