E1M1: Hangar (Classic Doom for Doom 3)

One of the most popular game Doom 3 was also input in Doom 1. They recreated Doom 3 and Doom 1 put together. You can do that by


 * Downloading the mod
 * Entering cheat 'give doom98' in the console. (Note: It only works in the full game of Doom 3.)