Hell Revealed II (HR2FINAL.WAD)

Hell Revealed remains an inexplicable enigma; for awhile, when someone would pop in and ask what they should play after having finished and loved Doom II, a sizable number of people would throw it out there. If I didn't know any better, I'd think they were trolling, attempting to turn people off Doom forever with HR's sheer difficulty curve. The truth, though, is that a lot of people love it, and when the iron was hot, some of its fans got together to make a sequel. Hell Revealed II took a lot longer to make than its forbear, though; about five times as long, in fact. Released at the very end of 2003, its influence is undeniable. I've seen numerous explicit citations when parsing the more elaborate commentary provided by PWAD authors. There are moments of sheer BFG frenzy sure to satiate fans of demon-reaping gameplay. Then, of course, there's the other stuff.

Exquisite Corpse (EXCORPSE.WAD)

EXQUISITE CORPSE
by Andrew "Linguica" Stine, Rachel "Shtbag667" Schmitz,
Jacob "Darksoul" Kastner, "Volteface", "Fiend", Mike "Cyb" Watson,
Simon "_5hifty" Rance, Chris "Chopkinsca" Hopkins, Boris "boris" Iwanski,
Maximillian Augustus "Blackfish" Daley, "Scrum", and Josh "Earthquake" Simpson

The 1024 fad hit Doomworld pretty hard. In some ways, it still hasn't recovered, though 2048 may yet take its place. 1024 levels limit the playable space to 1024 x 1024 units; the challenge to the author is to create a level that avoids feeling as restrictive as it truly is. Before the Cacoward winning Congestion / Claustrophobia 1024, though, there was 2004's Exquisite Corpse, from where 1024 ultimately originated. The project got its cues from a surrealist parlour game where authors join together to create sentences and images, the caveat being that each player can only see the very edges of what the previous author did.

Void (VOID.WAD)

VOID
by Mike "Cyb" Watson

Released in 2003, Void is a single Doom II map for ZDoom. But... It's a lot more. The story opening is basically Half Life in Doom, down to scientist voice clips, and when shit goes bad a Cyberdemon drops in and starts slaughtering your buddies. Before it can kill you, time freezes and Hexen's Heresiarch shows up, creating a rift that sucks all involved parties (and corpses) into an unusual dimension. You'll have to fight your way out, of course. Actually, fighting isn't as important in this PWAD, as you'll end slightly upwards of one-hundred monsters slain at the end. There is a much greater emphasis on puzzles, platforming, and platforming puzzles.

Congestion 1024 (1024.WAD)

Congestion 1024 is a Doom II megaWAD released in 2005, born from the Exquisite Corpse project, in which a collection of mappers created twelve 1024 x 1024 maps and bound them together as a single, contiguous level. I assume either those involved or those observing found the individual puzzle pieces so intriguing that they made an entire WAD out of similarly sized bits, creating 32 levels of intense action. The rules: the player is bound to a 1024 x 1024 area. They are allowed egress as long as they die upon leaving the 1024 confinement. Monsters, of course, are allowed to be outside the area's bounds and frequently are.