reminds me a little bit of thomas was alone just with the power unit added to it which could be a game changing aspect.
as of level design I think it could get pretty difficult to make working levels while keeping them individual and challenging but that would be something we could talk about together I guess.
Do you have some tilesheets or something to work with already? I have been using tiled a few times but never really used it in a game. And my knowledge in platformer games is very limited to super mario etc :,D
I've mainly worked on Top-Down, Isometric, 3rd Person(3D) and FPS(3D) games.