Too much effing CGI. After the trailer, I get this Ang Lee Hulk vibe most definitely. Yes, you are going to need graphics to adapt this material, but did everything remotely possible have to be cg? I learned my lesson with the whole gungan versus droids battle in The Phantom Menace.
That was definitely my concern going into the movie, because the trailers do push the CGI awfully hard (and I already found those long Asgard scenes in Thor to be pretty tedious).
But thankfully the actual movie is much more grounded and balanced than that. Most of the story takes place on Earth, and when we do travel to Oa, it's actually pretty cool and exciting.