ROTT uses the Wolf3D engine and was somewhat of a collaboration (if you could call it that) between id and Apogee!
ROTT is in my childhood's "badass games hall of fame" along with Quarantine (aka Death Throttle aka Hard Rock Cab), Abuse, and Stratosphere. Honorable mention: Microsoft Flight Simulator: Aircraft & Scenery Designer (MFSASD) for the ability to make an almost flyable U-2 from the jet plane.