I really liked this one. There's some obvious '80s influences here, from the criminals looking like something out of a Mad Max movie to the Short Circuit and Robocop elements. There's even a bit of a He-Man cartoon shown at one point. It's an intriguing and certainly entertaining movie, if not an overly original one. I think some critics are unhappy with the lack of pretentiousness that was present in Neill Blomkamp's previous work. Here the "messages" are more universal and less political. Some people only like their sci-fi if it carries with it an obvious metaphor for a topical social injustice. You can even find such metaphors here if you try but subtlety is not a zealot's cup of tea. Overall, I thought the script was good and I really liked the upbeat ending. Another nitpick I have about the modern critic is that they think the only good sci-fi story is one with a downer ending. The special effects are pretty amazing. The acting is solid all around. Dev Patel, Yo-Landi Vissir, Ninja, Jose Pablo Cantillo, and Sharlto Copley (voice & motion capture for Chappie) are all great. Hugh Jackman has a rare turn as the villain here and does a terrific job, even if I do hate the obligatory clichés his character is saddled with. That haircut, though...
Maybe it's not for everybody. I have friends that haven't seen it yet that I'm fairly certain will bitch about it and pick it apart, like I see from many reviews on here. But that's their loss. I'm happy that Blomkamp tried to make a movie that's not dumb by any stretch but also isn't just aimed at the elitist film snob crowd or soapbox bloggers.