I felt I was a bit let down by how linear the game is and also how repetitive the fighting is. It all gets too predictable as to what's going to happen with enemies.
I'm not going to spoil it, as OP obviously hasn't finished, but I thought the final boss fight was a bit of an anti-climax and not a proper fight. Also not too sure what to think of the ending, but it's clearly sequel material.
It's got good writing though and it's certainly worth a play through. I actually rented it though, as it's quite quick to get through... think I'd be disappointed if I'd bought it.