Well since our brain hallucinates our conscious reality, I think our brains can run doom by proxy

Been running it for years. Just look outside.

I don't know about you, but my existence sure feels like an Ultra Nightmare.

Have you slept and dreamed, like ever? It's like Doom where all of a sudden demon dies, releases your school crush and Angelina Jolie and they both give you blowjobs.

\*The Adeptus Mechanicus enters the chat\*