Backtracking makes the game. Part of the fun of it is playing through the same areas multiple times, and finding new things in each instance. I'd rather be backtracking than only visiting each environment once or twice. Consider the polar opposite.... a game such as Dungeon Siege.
I'm not a
huge fan of the control scheme, but it's justified in part as marginally mirroring the side-scrolling Metroid titles, with limited vertical control. It does become a bit cumbersome at times, though.