[GAME IDEA/CONCEPT ART] 3rd-Person Action-Survival Shooter

[Vipershark]

how about like
the drugs can make you hallucinate if you OD

your stress level will rocket past max level
resulting in randomly spawning monsters that keep reappearing and maybe something like you can't hurt them (since they don't exist) but they can hurt you (since you're imagining that they're real, your brain thinks it's real and physically injures you when they attack you)
and you can't see what's around you since you're hallucinating things are/aren't actually there