Although throughout the 'No Mercy' campaign you are heading for 'Mercy hospital' and can see it in many areas of the game due to the huge logo at the top of the building, when you finally reach the roof top, the 'Mercy Hospital' logo is missing during the final battle and helicopter escape.
The events of this game take place 2 weeks after the infection. Despite this, some vehicles such as police cars still have their lights on.
In the intro cutscene, Louis gets pounced on by a hunter while standing next to the left side of a car. But in the subsequent shots of Zoey running towards that hunter, gunning it down, Louis and the hunter are now behind that car.
Tracer rounds can be seen firing from shotguns. Shotguns do not fire tracer rounds.
The way that weapons are reloaded is incorrect. For example, shotguns only need to be pumped after reloading if all the ammunition was expended.
If Francis shoots Louis, Louis will sometimes say "Go on, do it one more time fat man!" referencing Francis' original design in the earlier stages of the game.
The view from the scope of the sniper rifle does not match the positioning of the scope on the rifle; the tracer round should be coming from beneath the scope, not from beside it.
The assault rifle holds 50 rounds, although it uses the 30 round magazine.
The acid blood of the Xenomorphs does not affect either the environment or players/NPCs.