Derivative and decidedly lacking in innovation. If everything feels stale (plot to gameplay), it's because you've seen it all before and- since this is spoiler free- played it all before. You just do A LOT of it.
While the plot- though certainly not novel- was interesting enough to keep me going through the repetitive gameplay, it was a "just barely" situation. The chief annoyance was just how it felt all the situations were contrived to bolster the length of the game. I nearly started pulling out my own hair. "Meet me here!" Okay. Oops. Walkway fell. Gotta climb through sludge. "I made it to the x!" "Great, but you gotta go to Z and the elevator is down." *sigh
Pretty to look at, and fun melee battles, but everything from the gameplay to the opening sequence to the "atmospheric" music, all tells you from the start that the only thing surprising about this game will be the utter lack of surprise.