I think my review is contained in one word: disappointment. I adore this fictional universe, the sense of realism and adventure it offers, but, well, I had been disappointed by the second installment, Arthur and the Revenge of Maltazard, and the third and last film proved worse.
This is the problem with films that either go too far, or not deep enough, and I felt there were many ideas in Arthur 3 but that we didn't go to the end of them, but there were also overly exploited concepts.The Minimoys' world is there, but I got bored by the ideas of the first and second films that are again at the center of the last one... and the new ideas are ended too fast. This is all a blurry mix up of the 1st and 2nd film.
One thing I cannot hold against this film, however, is the special effects: tevhnology is still there and that's a relief.