I honestly can't remember one aspect of the movie that I could say is worth having to sit through the rest of the movie to see. It sure as shit wouldn't be the 3D, which was awful to say the least. They did such a rush job on the 3D conversion that the whole movie just looked warped... like a curved mirror. In one scene, Sam Worthington's eyes appeared to be set back so far in his head that he could have been a villain in a Dick Tracy movie. The only part of the 3D that was mildly entertaining, was when he was flying on Pegasus through the Kraken's tentacles. That lasted for less than a minute though, so I'm gonna stick with my original statement that not a single thing about the 3D made this movie watchable.
Some other things that did not make this movie watchable are Sam Worthington's portrayal of the Australian Perseus, Ralph Fiennes's "VoldeHades", or -any- of the dialogue (but more specifically, Pete Postlethwaite's overly melodramatic "One day, somebody's gonna have to make a stand..." line).
Clearly I'm not a big fan of this movie. If you must see it, DO NOT see it in 3D.