first game:
-man finds himself in a industrial facility isolated from the rest of the world
-a portal to another world is opened and creatures invade the facility
-man shoots his way out and escapes

second game:
-man comes back home
-finds out the creatures have already invaded planet earth
-Doomguy shoots his way out and kills the Icon of Sin stopping the demon invasion

am I mentally challenged for only noticing the parallels now? I genuinely never saw any one mention this, why didn't you guys tell me?

...also this game is BOOOOORING!!!