I don't know what you are spoiling

I don't know, Game & Watch wasn't actually 2D in Melee because it was apparently difficult to make that work (though I can't remember why). His model was a 3D one merely designed to look 2D. Melee is also the game that introduced the Ice Climbers.

Besides, the AI would be the largest issue. They'd all three be working together, meaning there'd be even more programming required than the Ice Climbers.