Before Halo, Call of Duty, Doom, and even Wolfenstein 3-D, there was Catacomb 3-D, a prototype of the first person shooter. Catacomb 3-D is the third of a series, although it is the first using a 3-D engine. Playing as a nameless wizard, you descend into a catacomb to battle orcs, goblins, and other creatures with a variety of spells that you find throughout each level. The game was later followed up the Catacomb Fantasy Trilogy, which wasn’t developed by ID, although they use a similar engine and gameplay. These three games introduce new levels, and the third part even introduces sci-fi elements. You can get the entire series for only $6 at GOG.com. You’ll want to check it out and witness the birth of one of gaming’s most popular genres.