The game retains many of the elements of the original [[Doom games|''Doom'' games]], and is likewise played from a [[Wikipedia:First-person perspective|first-person perspective]]. However, the game is fundamentally different in that it is a [[Wikipedia:Turn-based game|turn-based RPG]]. All combat and movement is turn-based, allowing the player time to select their responses in combat. The player turns at 90 degree angles and moves space by space. Although visually similar to the original games, there is a greater emphasis on the plot. It is very important to speak to the scientists and access computer terminals to attain vital information in order to progress into the game, somewhat like in ''[[Doom 3]]''.
Many features of the original are retained, including the [[status bar|status bar face]], sound effects and the majority of the [[weapon]]s and [[monsters]]. Notably absent are the [[chainsaw]], [[Arachnotron]]s, and the [[Spider Mastermind]]. A difference from the original is that each monster type includes three similar monsters of varying difficulty, which are each coloured to indicate this. For example, in addition to regular [[Cacodemon]]s, the player will have to fight recoloured Cacodemons called "Malwraths" and "the Wretched".