Are there any other games that have done this? I was thinking about it last night and realized that this way of writing the story was actually pretty clever, yet no one ever took the idea and ran with it, despite this game being released right before "moral choice" systems blew the fuck up and everyone wanted to add on into their game.
No moral choice system
Sonic Heroes.
Sonic Heroes did it I think.
I can't really recall many games that let you revel in being the bad guy like Sonic Adventure 2. A lot of the marketing for that game was based around the evil story since it was a novel mechanic back then.
Games with moral systems let you be a jerk and all but there aren't many where you are actually playing the villain of the story. Overlord and Dungeon Keeper are the two that readily come to mind for me. KotOR let you join the big bad in the end and Infamous had a moral system that actually painted you as a villain if you were evil, but those both use morality systems instead of a straight up bad guy story.
ow the edge did it
That was shit though, most (all?) stages were recycled and the writing was basically the same.
That was a branching path though. DOesn't matter because that game was horrible.
Pic related offers the player a chance to play as the bad guys in an evil campaign though i think it may only be unlocked after completing the hero story mode.
Whats fun about it though is there are multiple characters for each campaign including secret unlock characters.tied to gold collection during levels.
Oh right, Fire Emblem Fates also did what you're thinking of, kinda.
Transformers War for Cybertron series kind of tried that, but they didn't have a true final boss, except maybe Fall of Cybertron. But they didn't let you choose which side you want to play as. A bunch of Sonic games did that mechanic for a while, until it got really tiresome as they were just forcing you to replay levels without adding anything new. Also Shadow the Hedgehog.
Transformers is honestly the ideal series for that sort of thing. Even in the original animated series, there were more than a few occasions where both sides had to work together for one reason or another. There's even one episode I remember where Megatron turns into his gun form and lets Optimus use him, and the two proceed to lay a major smackdown on the Insecticons they're fighting.
Nowadays there's this major obsession with making Megatron into some sort of massive edgelord root of all evil and other shit like that, which kind of fucks things over. Transformers is one of those things that can only be good when it's not taking itself too seriously.