E2M7: Spawning Vats (Doom)

E2M7: Spawning Vats is the seventh map of The Shores of Hell in Doom. E2M7 was the first level started for Doom, and early versions appear as E1M1 of Doom 0.4 and E1M11 of Doom 0.5. It was designed by Tom Hall and Sandy Petersen and it uses the music track "Waltz of the Demons." The par time is 4:00.

As the last of the levels representing man-made complexes, Spawning Vats is in effect an amalgamation of all previous bases, including a container warehouse and a computer complex.

Walkthrough
At least on ultra-violence and easier, if you warp in and start with the fist and pistol, avoid fighting the demons in that room where you start out. Instead, dodge them and run to the right (west) corridor, which will bring you to the room with the blue key door. There, you can dispatch a sergeant to get his shotgun, pickup a box of shotgun shells, and then take down the two demons easily. Do not continue past the blue key door room yet, as you do not have the ammo to deal with the tougher monsters yet.

Beware of the door that closes behind you when you enter the descending stairs to the crate room (warehouse). Before you step on the stairs, use a couple fist punches to alert some demons, which you can dispatch before getting trapped. Getting the berserk will allow you the dispatch the rest of the demons easily. Save the invulnerability for taking on the baron and cacodemons outside, where you can save ammo by using the berserk fist.

Be careful when you go through the yellow key door, as there are a large number of imps behind it and they will have been alerted to your presence, since that area is connected to the outside where you fought the baron and cacodemons. Also avoid the middle trench of the hallways which are illuminated by blue lights, since these will reduce your health.

Secrets

 * 1) In the hall connecting the warehouse and the outdoor area in the east, climb the small staircase leading to a small control room. Follow another set of stairs down to a switch. Flip it to open a secret room behind you.
 * 2) In the corridor lined with hemi-cylindrical "vats" in the west, there's a narrow opening between two of the vats on the west wall that leads outside.
 * 3) At the north end of secret 2 is a switch on the wall. Flip it to open another secret area.
 * 4) In the room in the southwest with several small slime pools in alcoves. In one of these alcoves is a small tunnel leading to a rocket launcher and a teleporter.
 * 5) After getting the red keycard, go through the teleporter in secret 4. Open the red door and flip the switch behind it.
 * 6) After flipping the switch in secret 5, as well as the switch behind the blue door, go all the way back to the starting room. A nook holding a soul sphere and a bulk cell will be accessible.

Bugs

 * Two "hanging leg" decorations (Things 192 and 193) and an energy cell (Thing 99) have no flags set for any of the difficulty classes, so they do not actually appear in the level.
 * In this level it is possible to trigger an example of the Tutti-frutti effect. Upon entering the crate room, a door closes behind the player.  The door consists of two sectors.  By blocking the second sector, it is possible for one sector to be closed while the other remains open.  A short texture which does not vertically tile is used for the linedef between the sectors: as a result, the tutti-frutti effect appears.
 * Early versions of this map had several linedefs with flag bits 9-15 set (which apparently had no function).
 * In the southeast courtyard with the two small nukage pools, two corpses hang from the ceiling despite it being open sky.
 * Linedef 1286 (just in front of the south side of the yellow door), lacks a lower texture causing a small HOM effect.
 * A Reject table blindspot causes the demon behind the blue key door to not see the player in front of the door.

Records
The Compet-N records for the map are:

Trivia

 * Spawning Vats is the final level for the 32X version of Doom.
 * Spawning Vats contains one of the rare instances in official Doom levels of a non-animated damaging floor, a row of blue lights in a trench.
 * Spawning Vats was originally designed to be a hangar, as the alpha versions of the map are based on the "Hangar 2" area in the Doom Bible.
 * The PlayStation, Saturn, and 32X versions of Spawning Vats don't have any physical vats in the level itself. They also contain a secret exit to E2M9: Fortress of Mystery.
 * Spawning Vats is the largest level in Doom. Conversely, versions of Doom such as the PlayStation and Saturn releases contain a significantly simplified version of this level. It is presumably due to hardware limits or concerns over confusing layout. This is also partly due to this map being a derivative of the Atari Jaguar edition of this map. The textures have also been changed significantly to largely a Doom-2-themed "rock and mortar" theme.
 * The first Doom novel mentions the spawning vats, describing them as having the ability to "cook" a new monster with artificially-made flesh and bone.