Doom - Operation: Biowar - Operation: Biowar

Operation: Biowar is a 1999 mod for Doom II: Hell on Earth, offering a 19-level megawad experience with a blend of techbase, Hell, and new snowy mountain themes. While retaining classic Doom gameplay, it introduces new sound effects, textures, and music by Mark Klem. The story follows a new protagonist uncovering a diabolical scheme involving the UAC president and a demon named TCHERNOBOG, who are trading souls for demonic biological weapons. This mod's uniqueness lies in its extensive level count and thematic variety within the Doom II engine.