1. More characters and more of a variety in characters.
I thought the characters they had in the game were cool, but I wanted more and I think they had slightly too many Batman characters for my taste. I understand Bamtan is DC big cash-cow and all, but this is a game that should explore all of the DC Universe not just a few aspects of it.
2. More Villains
This falls in line with number one, but I do think the game needed more villains.
3. More moves and special moves for each character.
The characters in game had some cool moves, but I feel like they could have done more with the variety in moves. The move list needs to be more dynamic and not so repetative, each character should at least have two special moves maybe one can cause more damage than the other.
4. Improvement in facial features and better looking female characters.
I feel like the games graphics were top notch, but the female faces especially for WonderWoman looked extremely off putting. Absolutely no reason why every woman shouldn't have been drop dead gorgeous. Notice how it looks very strange the way their face moves, it's more so the teeth.
5. Longer story and more original plot.
The game had good pacing and the story was good, but the whole alternate universe story has been done to death in the DC Universe.