Bethesda added a new level pack to the original Doom. The add-on is called Base Ganymede and is the work of modmaker Khorus. It contains 27 levels over three episodes that, like the original, go from army bases to hell.
Base Ganymede was released in parts in 2009, 2010 and 2012 by mod maker Khorus. Doom fan site Doomworld awarded the mod with a Cacoward in that last year, an award for the best Doom content of that year. The fansite: “Base Ganymede is a mega wad overflowing with personality and charm. The maps showcase the Khorus design perfectly, being medium in size with interesting layouts and monster placement, but they’re also very experimental, because they require the player to think about combat in unusual ways.”
This add-on is now downloadable within Bethesda’s modern Doom port, via the appropriate menu. Other Addons to be found there are Sigil, from John Romero himself, and other mods like Arrival and No End In Sight. This modern Doom port is available for Windows, PS4, Xbox One, Switch, iOS and Android.