I installed this game on a friday afternoon and by saturday i had finished it on normal.
Its a great game with great ideas and enjoyed playing it, it does need a high powered rig to play it nicely as is mine.
it falls short on a few parts though as end of chapter trigger points can be annoying as you may want to explore some more before completing a level.
But what a great touch is the toys you get to play with , tanks, helicopters, remote control gun turrets, remote control helicopters and many more.
I enjoyed it so much i will be replaying it on hard next :)