Public Domain Superheroes: The Game

I have been working on a little project for over a year, and I wanted to put my feelers out there to see if there if I can get any enthusiasm out there for this kind of idea.

I've been fascinated with Public Domain Superheroes for years. While most of the really popular comic book characters are basically locked down by Warner and Disney, now, the idea that these characters can be used without any cease-and-desist type ending fascinates me, and it surprised me it hasn't been tried yet.

So for over a year I've been working on a game, a 2D sidescroller-beat-em-up inspired by the kinds of licensed games I played as a kid, except instead of Batman and Wolverine I'm putting The Black Terror and Twilight in there.

So my point being...Which public Domain heroes would you like to see in a game? And why do you think no one has tried to use this characters in videogames? Is this even posted in the right part of the forum?