freedoom binary package in Ubuntu Focal amd64

 The Freedoom project aims to produce three base-game data files
 (IWADs) for Doom-compatible engines. With it comes the
 capability to also play the wide range of mods created for Doom
 by a vibrant community.
 .
 Freedoom: Phase 1 contains four chapters, nine levels each, to
 provide a smoothly-paced first person action game. In it is a
 wide variety of mazes and enemies to fight and challenge your
 reflexes.
 .
 Freedoom: Phase 2 is a 32-level game, expanding upon Phase 1 and
 adding a double-barrelled shotgun and more enemy types, along
 with even more brutal gameplay to really test your limits.
 .
 Freedoom: Phase 1 is fully compatible with The Ultimate Doom mods.
 Freedoom: Phase 2 is fully compatible with Doom II and Final Doom mods.

Source package