|All levels take place within a highly confined space.|
Congestion: 64 is a joke megawad inspired by Congestion 1024, and following a similar premise, namely that all levels fit within a small area. Congestion 1024 restricted mappers to a small but nonetheless workable 1024x1024 unit area, but in Congestion: 64, all levels are restricted to a tiny 64x64 area (by comparison, the Doom player object is 32x32 units in size). While Congestion 1024 was a community project, Congestion: 64's levels are all authored by a single mapper using the alias "1337 Doomer".
Despite the WAD's joke premise, a surprising amount of creativity is shown in use of the limited space. The first few levels contain only a small 64x64 room and an exit switch, but later levels exploit many different features of the Doom engine, such as keycard-protected doors, rising stairs, moving floors and elevators, and one even manages to include a teleporter. As one example, one level presents a puzzle where a correct elevator must be activated to lower a keycard that opens the exit door; if the wrong elevator is selected, a barrel is detonated, immediately killing the player.
A common source of confusion is MAP14, which includes an exit switch behind a door that will only open five minutes after the level's start. Without cheating, the only way that this level can be completed is to patiently wait the full five minutes for the door to open. As a result, several players (in reviews on the Doomworld idgames site, and on Youtube playthroughs of the WAD) wondered if the level contained a bug.
A number of levels seem to follow the Doom II's original levels: for example, MAP06 ("The Crusher"), contains a crushing ceiling, and the player must quickly press the exit switch to avoid being crushed. MAP23 ("Barrels of Fun") contains a room with three barrels, while the secret levels (MAP31 and MAP32) are Wolfenstein and Commander Keen themed.
Congestion: 64 was released several days after Congestion 1024, and because of this, both appeared together in newstuff review.
The first zombie
The mandatory nazi
Yes, there is a teleporter
The lost soul
Beware the barrels
Ouch, a baron of Hell
The icon of sin