I had an idea for a game recently (though I suspect it won't be any more successful than anything else I've tried of late, but I digress) that I think I would best describe as the 2k3 Teenage Mutant Ninja Turtles animated series crossed with a little Street Fighter and Xiaolin Showdown.
However, to get the feel right, I'd have to be extremely limiting on PC options. I could see allowing one human PC (to be 'The April' or 'The Casey', as it were), and perhaps letting one PC having psionics or mystical powers. Of course, everybody has some kind of martial arts and probably some weapons and miscellaneous gadgets like smoke bombs or whatever.
But there were regular superheroes around, and super-high-tech, and aliens, and all kinds of mystical stuff (especially in the lost episodes that aired on CW4Kids). Given that, I'd probably set the game in a somewhat stripped-down version of the Champs U ... take out the huge heavy guns like Dr. Destroyer, focus more on agencies like VIPER and DEMON, reduce the overall super-population both heroes and villains worldwide.
Somehow, though, it seems unfair for me to have the PCs have to be restricted to animal powers, martial arts, and weapons with possibly one low-powered mystic or psychic, while there's all this other stuff flying around. Though some of it could be picked up along the way with XP ("I'm gonna spend the points to start hiking around with this laser rifle I swiped off a VIPER agent, cool?"). Am I merely being anal-retentive, am I seeing a problem that isn't there, or is this a legitimate concern?
P.S. I know that if the players all accept the limitations without reservation then there's not a real problem, but, assuming this does qualify as unfair, I'm not the sort to treat my players unfairly even if they're willing to accept it.