FPS depends on the engine. Since the HL engine is pretty crappy, anything near 30 fps or below gets choppy. In a game like, COD, 30 fps looks like 100 fps in HL. 30 fps in HalfLife2 would probably be smooth as glass, but don't expect to get that on high settings or anything.
I've never really thought about this until now, but in HL1 as you're playing through Xen, who the hell are all the dead bodies that look like they're wearing hazard suits? I just thought about them, and was like wait a second, wasn't there only 1 portal which was really hard to bring up? How did...
Besides that, don't you think those combine suits look kind of hot and stuffy? I want to get those guys a glass of water just for wearing it.
Anyways, about the part of how people know Gordon. I'm assuming everyone in the world knows about Black Mesa and how thats where the alien invasion...
If you look in the tech video you can almost kind of see that "bricks" effect in it. I kind of noticed it after I saw the unreal movie but thought I was seeing things cause HL2 never made a big deal out of that.
FarCry was ok but the ragdoll was kind of crappy. Shoot a guy and he slowly slides down a tiny hill for 30 minutes, and most of the time they didn't look or bounce real.