Doom Eternal ➔ Classic Doom

While some of the games on this list make it very easy to find their hidden bonuses, Doom Eternal is going to make you work if you want to play either Doom or Doom II.

Last year’s superb follow-up to 2016’s reboot of the Doom franchise contains both of the original games in the franchise, playable on a PC in the Doom Slayer’s headquarters in the Fortress of Doom. But they’re not so simple to get at. For 1993’s industry-redefining Doom, you need to collect all 14 floppy discs (otherwise used to unlock cheats) hidden around the game. With them all, “File 1” becomes accessible on the PC, and Doom is yours to play.

For Doom II: Hell on Earth you’re going to need a password. “File 2” is also locked, but you can access it right away just by selecting the letters to spell out “FLYNNTAGGART”. (Flynn Taggart was the name of the protagonist in—deep dive time—the original Doom novels!)

It’s worth noting that PC Gaming Wiki reports these versions of both games are censored, Doom being the PSN version, and Doom II being the Bethesda.net edition. You can fix this if you so choose by swapping in an original DOOM.WAD into the folder baseclassicswads.