Sure there are two sides to everything. Some things though it is very difficult to imagine as being valid from the other perspective. Consider that game you're playing, Kindergraphics Portable Entertainment Game System 64 "Super Koopa Troopers".
Ok, so you play as a turtle, which gets super powers by eating various vegetables, protecting the land of reptiles from the encroaching rot of the fungal kingdom, whose armies are led by, of all things, a plumber. Now, I understand that it is just a silly video game and they generally require very little in the way of justification, but can you imagine how bizarre and twisted the justification would have to be if you were to play as the other side? Nothing against plumbers, I'm sure that such an industrious mechanic would work as a fair enough role model everyman, but he'd have to be on the side of the reptiles to come off as heroic. Not even you could imagine mushrooms as the "good guys", half of them are toxic, and despite their individual weakness they aren't even the underdogs, in the long run decay and entropy always win.