Games like this are the reason GRIN was closed.
The game is entirely linear and will even go as far as to give you weapons before and during every fight, so there's never any surprises there. There are also only three types of enemies, four if you count the ships that you fight a few times. Because of this, you will only recycle strategies to beat them once you figure out their weakness.
What makes this game hard is the awful AI, both friendly and enemy. Enemies will stand in one spot and shoot at you in cover, even if you move. You are supposed to flank enemies while your teammates keep them busy but that simply doesn't happen. As a result, you basically spend most of your time sitting behind cover waiting for a moment to pop up and shoot something.
None of the characters share their movie likenesses from what I can tell. Overall length is around 6 hours on hard, and that's with some trial and error portions. For achievement junkies, the full 1000 is fairly easy, but a real headache. Stay away unless you REALLY like the Terminator universe...Even then, you can do better.