It gets some points for trying to be creative with the two player puzzle solving, but that same feature is its biggest downfall.

While it's possible to play this game solo, it defeats the entire purpose of the setup by basically just having you switch back and forth between characters once you clear their individual segments which begs the question of why even bothering to have two characters if they aren't working off of each other. The obvious and unfortunate answer is that AI probably wasn't good enough to follow you around correctly which basically meant you either had a tedious single player game with extremely frustrating boss fights to play by yourself, or you were at the mercy of having someone else around to play the game "properly".