It combines the Doom first-person shooter franchise with role-playing video game elements.

The storyline incorporates many similar events of Doom 3, but involves different characters than those in the third game.

It is very important to speak to the scientists and access computer terminals to attain vital information in order to progress through the game, similar to Doom 3.

Many features of the original are retained, including the status bar face, sound effects and the majority of the weapons and monsters.

A dog collar-styled mind-control device allows the hellhounds to be captured as pets, which can then act as both a melee weapon and a shield.

The story occurs on a Martian Union Aerospace Corporation installation similar to Doom 3.

Three weeks prior to the start of the game, Guerard asked Graff to perform a security audit on Jensen.

Early on in the game, the Marine meets Dr. Jensen when he was accessing a computer terminal investigating his dismissal.

During the exploration of first few sectors of the installation, the Marine receives help from Dr. Guerard in gaining access to various locked down areas.

In Biological Research Facility, the Marine meets Dr. Nadira who quarantines his weapons claiming security measures.

After defeating Kronos, the Marine closes the portal by destroying the reactors powering it.