While at GDC, I had a very early first-look at a game called The Showdown Effect which revolved around playing as an action movie stereotype. What I was shown was more of a very early prototype (almost still even an idea pitch) of a game, though I did have a chance to actually play some of the pre-alpha build.
Based on what I saw, I could easily see how the ideas being thrown around by the developers could be well implemented into The Showdown Effect.
The Showdown Effect (PC [previewed], Mac)
The very early build of The Showdown Effect I was shown provided one map of a "Neo-Tokyo" environment that had stuff actively going on in the background while your player and one other runs and leaps about the environment in dramatic action-movie style. Though I didn't get to see it in action, I was told by the developers that one of the main ideas behind The Showdown Effect involved using one-liners at opportune moments as you fought other players across the (admittedly pretty large) 2.5D maps.
The idea is that you choose a character among several action movie stereotypes gleaned from movies like Rambo, Alien, or Die Hard. As each character battles, you have a button that spews forth a one-liner that grants you extra points when successfully done, such as after a kill. From what I was told using a one-liner is a risk, as you may be killed by another player in the middle of your sentence and receive no bonus from it while looking like a total fool.
In the map that I ran around on, weapon pickups were numerous with SMG's and shotguns as well as a rocket launcher and a katana. The art style was reminiscent of Shadow Complex, with large side-scrolling levels and random stuff happening in the background. I struggled a little with the controls simply because I'm more of a console player, but I was told by the developers that gamepad support was going to be implemented as well.
One of the mechanics still in an early implementation is bleeding damage, where a character who is hit by bullets begins to spout out blood and has to find a safe spot to bandage themselves in order to fully heal. The graphical effect of this was neat, though I wasn't sure how much of an effect on gameplay it would have in a regular session.
I really dug the style of The Showdown Effect, but I couldn't get a good feel of the final product from the very early pre-alpha build I was shown. As is the case with early previews of games like this, a whole lot might change before the game is released. I can say that the developers are certainly headed in an interesting direction for the game, and I look forward to a preview of a more finished product in the future.