Thanks, GeometriX, I understand it's pretty hard to help without anything to go by.
To tell you the truth, I actually don't mind sharing the .capx at all, in fact I eventually plan to make it open-source so that others can help expand it.
I just don't want to violate any forum rules. Am I allowed to post a game with Mario, Megaman, etc, in it? If not, I'll do what you say and replace the sprites with simple shapes.