A Masterpiece in the First Person Shooter genre, Wolfenstein may have been it's grandfather but doom is the true father of the genre. It's eerie, it's violent, it's very good fun. Obviously nowadays map makers could make WADs ten times more coherent than this so keep in mind when playing this for the first time that there are parts of this game that can be confusing aspects of the level design can be maze like at points but overall it's understandable 90% of the time. In terms of episodes I'd say the first and second are best and the third is the weakest while the levels aren't awful and there is still good fun to be had but episode one and two feel much tighter. (I also think the amount of hurt floors towards the final few maps of the third episode are a bit much) Really the only map I outright disliked was Slough Of Despair it's not my favorite but overall this game is great Absolute classic.