A little kid who lives with his grandfather shrinks himself, with the aid of his teddy bear, in order to go inside his grandfather's body to see whats making him ill. With the help of two "people" he meets on the inside he sets about making his grandfather well.
Sue me I really liked this movie. I have no idea why I should have warmed to this kids film but I did. Perhaps its the design (which is just neat to look at) and the sense that there is something behind the story beyond just being a live action Osmosis Jones for kids (it is very clever a good deal of the time). This is a kids film that just tells its story and so it becomes something more than just a kids film.
No, its not perfect. I find the talking teddy bear oddly done, the real world stuff just misses and the pacing is off, I'd have liked it move not so much faster as differently, the rhythm seems off somehow. Still I liked it. I'd give it a 6.5 myself, with a 6 for the IMDb since in many ways its better in the parts than as a whole.
Definitely worth trying if you run across the film, especially if you are open to good, but not great kids films with really cool looks to them.