@Emmi: Problem with that is that your statement is completely incorrect.
OT: Think about it as an imagination game. You can create unique ways to get through the levels, yes, but the story mode is actually just a small side portion that was 'tossed in there' a 'la Brawl's Subspace Emissary mode. The real meat is just the ideas you can come up with.
Feel like taking a bunch of blocks, building a rock'em sock'em robot, and duking it out with a friend? Go for it. Or maybe you just feel like making a catapult and hurling yourself into walls .
I can't wait for this game