A tiny tale to hold your attention for an hour or so. As always Ghibli animation it top notch, but it isn't enough to make the movie great. I'm not saying the movie is bad, it just doesn't have that high stakes or proper ending like other Ghibli films like Howl's Moving Castle and Ponyo suffer from. There is no real climax and the way Ponyo ended I should have expected that.
What you get is a brief look at a beautiful world from a tiny person's perspective. With tiny inventive tools made out of things we use all the time reworked for little people and stunning animation that you wish you could see more of with great perspectives based on one's relation to size. Arrietty is a brave young girl, that you get know, but her story isn't that memorable. It seems like a prelude to a bigger adventure that will never come.
I recommend it as a rental or a purchase on blu-ray, just wait for a fun little story about little theives that might be living in your house... and are watching you while you sleep.