Sonic have you ever played Crackdown? I haven't played prototype and honestly don't think I ever will unless I get a Gamefly account. But from your review it really seems like you would enjoy a game like Crackdown. It has the exact same superhero sandbox feel to it and then some. Crackdown 2 is coming out soon too I believe so maybe you would like to give that one a try (and its shiny new graphics) instead of the original its up to you.