Saw this a couple of days ago, in the 3-D version. And the animation and 3-D effects were absolutely great.
Unfortunately, the story didn't do the effects justice. I visited the IMDB and was quite surprised to see it rated as highly as it was - over 6.5. Not that I place any credence on quality as judged by what IMDB users think - judging by their message boards they're bombarded by pre-teens who like to put each other down...
Anyway, Lewis is a young boy, aged 13, who was abandoned by his mother on the steps of an orphanage when he was just a baby. He makes disasterous inventions which succeed in ruining any chance of getting adopted, and he's inventing at all hours of the day and night which prevent his roommate Goober from getting any sleep.
Lewis decides to invent a device which will recall his memory of 13 years ago, so that he can remember what his mother looks like and find her. He invents the device...and then Bowler Hat Guy - a black clad villain who looks like Snidely Whiplash and acts like Jim Carrey's Riddler - comes on the scene and sabotages the machine so that he can still it, and make a fortune.
Lewis runs away from this latest debacle, up to his roof top hideaway, where he is accosted by a boy (Wilbur) who says he's from the future. They have to save the world from the Bowler Hat Guy.
Lewis gets on board the other boy's time machine and travels into an Utopian future...which all of a sudden turns into a distopian one...
The first 15 minutes of the movie are mind-numbingly slow, as the premise is hammered down - Lewis is always looking back, wanting to find his mother, instead of looking forward, to new parents, new events, etc. Just as I was getting sick of his whining and wishing he'd just get over it, the 'adventure' part of the story begins...and its not until the end of the movie that the moral, to indeed 'get over it and go forward' is brought home.
There's quite a bit of filler that got on my nerves, even though as set pieces they were all right - singing frogs, a search for the garage that takes entirely too much time and is supposed to be funny but in no way is...and a vicious Tyrannosaurus Rex that can't capture Lewis because it has a big head and teeny tiny arms. (Yes that is a very funny scene. And then there's a bowler hat with many spidery steel legs, looking like a creature out of a ninth Doctor Who episode.
If you want to see it - see it in 3D. You get to keep the pair of cool glasses that they hand out for the film.