Half of the F3 levels felt like they took place literally next door to MW2 levels. Especially the suburbs... The suburbs, where at one point a waist-high wooden fence prevents you from running away from a squad and a power armor. There's a gate in the fence, but it's magic - it opens only after you wipe out the enemies.
I also chuckled at the way Fettel was invisible to the characters in cutscenes and could phase through solid matter, but in gameplay everyone fired at him, while he had to look for ways around iron bars. Can these guys keep their own universe consistent for at least an hour? Could they ask John Carpenter, who apparently "narrated" the game?
Oh, and the fucking wall-spawning troopers. Great game design: stick the player in a set of fridge-sized rooms and have guys with armor up the ass pop out of walls to shoot you.
Funny detail - in the demo of F.3.A.R., they dragged into one expo, Alma was actually able to rip you out of the power suit into her dream world. Never happened to me once in the full playthrough, so yet again the mech action had no relation to the rest of the game.

The third annoyed me even more than the second, because they completely buried the original AI and filled the game with randomly spawning generic brainless monster dogs, zombies and infinite spawners-Phasecasters. The graphics were often a mess, too: blur, bloom, wound effects, muzzle flashes, plot telepathy static, smoke, Fettel's hunger - you just can't see shit, when all that is going off at the same time.