Not so long after Wolfenstein 3D changed the world, ID Software made another game of that kind. Viewed from your perspective and in real time, it's just you and a weapon against the world.
This time, you won't just have a pistol, knife and a couple of machine guns, but much more powerful weapons like a rocket launcher, shotgun, and even a chainsaw if you're a blood-thirsty opponent.
The reason for the new weapon arsenal is that you deal with non-humans this time. Whatever seems strange to you, just shoot at it, fire at will, because there are no potential friends here. You're left to your own destiny, which ultimately can be changed if you're not too afraid to step into this realm of dark beings and tomato-like monsters.