I really loved the game up until about the time you entered the alien ship. The scenery and everything was amazing and ran decently on my 8800GT @ high. I love sneaking up on koreans and throwing them off cliffs and into walls
After the ship though the game seemed more focused on graphics/movie than gameplay. Also the carrier end battle ran at like 2fps for me lol. In sum: I hated the ending but loved the game. Time to try MP!