it's not even worth a rental. 2 weapons, shitty graphics, assy controls, no multi, extremely unfun turret sequences that couldnt possibly feel more out of place, boring level design (very corridor-y with almost no branching paths or alternate ways to complete)
and yeah it is like 4-5 hrs long. i beat it on assassin in less then 5 hours
turning in this game is worse then it is in killzone 2. which is quite an accomplishment