I would not make an MP shooter. Tthere's too many around we can't compete with, and who'd wanna play a 3dgs mp shooter if he/she can play CSS or Halo?

MP, sure. I'd be willing to give that a try. Shooter: no thanks. Too much prediction + interpolation, as Superku mentioned: Too much requirement for precice position.

I'd go for top view or even side scroller. Click-and-Go sounded good, as someone mentioned earlier.
We could make Blink's video link into a game: You're the developer in search of THE story.

Or not.