Fragport

Fragport is a megawad created by Stephen Clark (The Ultimate DooMer). First released in 2001 (with a later 2011 update containing minor fixes and adjustments), the WAD is notable for its seamless progression between most of the levels, with each new map's initial area being introduced by the previous map's exit location, as well as its penchant for attempting to create more life-like environments than some of its peers.