Is this game underrated? Maybe. Is it still hard to rate more than 6/10? Definitely.
At the end of the day it's just a pretty decent shooter than happens to take place in Rapture, there isn't enough gameplay variety and I sometimes thought the game was taking me where I've already been when it was supposed to be new locations.
Even when I first played this, it occurs to me now, I never finished it. So this is actually my first time beating it. And I hoped I'd think more of the game by the end.
There's some interesting things in the story, when the game remembers it has one, and even then it seems more than half-baked.
Not much else to say.