DOOM Eternal is not only an evolution of the DOOM formula with its action being better than ever, but it’s also a love letter to the franchise’s past with Easter eggs and callbacks aplenty. One such callback is the ability to play the original DOOM game within DOOM Eternal, kind of like a Pimp My Ride situation.
To unlock classic DOOM within DOOM Eternal, you must unlock every single cheat code by finding secret floppy disks, as well as by upgrading your Praetor suit. For how to unlock every single cheat in DOOM Eternal, check out our video below.
Note: you will need to have pretty much completed Eternal’s story before you can claim all of the cheats, and you will also most likely have to go back and replay some missions to find any cheat codes you may have missed. We’d say this will probably take you between 15-20 hours.
Once you have all the cheats unlocked, venture over to DOOM Slayer’s personal room in the Fortress of DOOM and find the classic PC on the right hand side of the room.
Select DOOM and then enjoy some throwback ultraviolence. Oddly, our DOOM Eternal always crashes when trying to play classic DOOM, which is just kind of funny. It looks like you can also play DOOM II on this PC; guide incoming for that one as well.