I seriously think this should be done in Game Maker. If you do Winged's idea of jumping, it'll seriously be hard because of landing, moving in the air a bit, running affecting the jump, etc. Game Maker was made for things like these and I agree with Chaos. RPG Maker was for RPGs, not side-scrollers. I don't want to put a negative tone on what I said, though. I just think it will be easier with Game Maker.