: Critical to success are the Sentinel Crystals found throughout levels like Exultia and the Cultist Base, which provide essential upgrades to health, armor, and ammo.
: One of the most famous secrets is found in the Slayer's room within the Fortress of Doom. By interacting with a PC and entering the password "Flynn Taggart," players can unlock a fully playable version of DOOM II . : Critical to success are the Sentinel Crystals
: Serving as the central hub, this command station contains various collectibles, including guitars and comic books, humanizing the otherwise unstoppable Slayer. Critical Reception which provide essential upgrades to health
: This specific enemy type sparked debate within the community, with some players feeling it slowed down the game's characteristic "push-forward" combat flow. Secrets and Easter Eggs this command station contains various collectibles
