This is a very good film. I did not want to watch The Last Mimzy, because I thought it would just be a silly kids' movie. Movies for kids these days are very often very boring and unimaginative, and they both insult the kids' intelligence and teach them nothing new. Also, although it might be harmful for the child's imagination, most kids will enjoy simple movies anyway, but most adults will find them too silly. The Last Mimzy stands out as a kids' film, as it's interesting, imaginative and non-patronizing, for a kids' film, and it can surely be enjoyed by adults as well, especially those who like (literary) science fiction (the movie is an adaptation of a story by Henry Kuttner and C.L. Moore).
There are very many good things about this movie, but a word of caution is due at first: although this movie CAN be fun for adults to watch (like many other films that kids can enjoy too, like the animated My Neighbor Totoro), it is NOT a mature film with children and fairly-tale themes in it (like, for instance, Pan's Labyrinth). It is a good kids movie, and should be considered and judged as such.
The CGI effects and the sci-fi-esqe gimmicks are all very cool, and all the performances in the movie are exceptional, with the female lead deserving a special mention. Somewhere half-way through the movie I noticed the seamless performance by Rhiannon Leigh Wryn - having not been aware of it before for the simple reason that it is so good that you are just watching a kid responding naturally to the situation she's in (and then you realize she's actually acting and delivering lines).
I would have given this move a much higher rating if not for the looser writing and editing in the last 10-20 minutes. It seems like suddenly someone realized they had to make the movie end and they only had 20 minutes to fit the rest of the movie in, instead of 2 hours, so what we see of the plot is really jumpy, and it somehow affects (or is affected by) the editing too. However, even when the quality of the movie goes down for the last 20 minutes, it is merely as bad, plot and editing-wise, as Artificial Intelligence: AI, and a lot of people think AI was a good movie - which means that 45 of The Last Mimzy is A LOT better. My dissatisfaction with some of the plot-holes at the very end diminished somehow when I realized that this was not supposed to be a hard SF movie, but a kids' film, so a lot of what happens does not have to be explicitly justified, and can be considered metaphor or something seen from a kid's point of view.
Anyhow, I seriously recommend this movie for people who like good sci-fi movies, as well as for people who have kids and would like to watch a movie together. One interesting point about this movie is that it portrays a positive view of intellectual giftedness, neither showing it as something akin to magical powers, nor as a disability, so gifted children could relate to those themes in the movie well (although they might benefit from the emphasis on a sci-fi explanation of some of the plot in a follow-up discussion of the movie).
Review by symbolt
from the Internet Movie Database.