Wow, just wow.  This game is such an improvement over the first game, it's amazing.  Granted, I just played the first few missions and just got my ship, but the combat has been so much improved.  The shooting feels responsive and the frame rate seems noticeably better than the first.  The graphics have also been stepped up a notch.  I am really impressed at this game right now...however, I still think that the Joker character model looks kind of janky--especially when he talks.  Looks like he isn't opening his mouth all the way open to talk or something like that.  Oh well, they couldn't have fixed everything.