Well-paced shooting action. Some parts can be annoying unless you figure out the right way to do them. Very addictive.
What I most like is using headshot because the "headshotted" robot atacs the other ones (robots). Often boss fights are challenging but not too much (and that is the right way IMHO). Some of the boss fights reminded me of Lost Planet giant animals fights.
Some scenes was annoying due to way of controlling ... especially the water jetski sequence (I have to go through it almost 30 times before I successfully did it).
As a sci-fi fan I like both the story and the way of storyteling (cutscenes, flashbacks etc. - dosed accurately).
I think this is very good shooter with not best but nice visuals, good story, fine storyteling, addictive action and decent game play time (about 18 hours) - so it definitely deserves i's 8.