Doom II: Maskim Xul is a Doom II WAD released by James Caldwell in 2017, influenced by the works of H.P. Lovecraft. The game features new monsters, items and weapons, as well as puzzle-solving mechanism in addition to fighting demons. This WAD was one of the winners of the Doomworld's 2018 Cacowards, and its map are named after the supposed Ancient Sumerian phrases.

Dimon12321 completes the game while killing all monsters and revealing all the secrets in the game as fast as possible.