MAP19: The Spiral (Doom 64)

MAP19: The Spiral is the nineteenth map of Doom 64, designed by Tim Heydelaar. The level basically is killing loads of monsters in a large room which has a large staircase in it. If you look at the map from your automap, the level appears as a spiral. All you have to do is grab a red key and kill all the monsters that teleport in. Then you can go into the red door room and kill the last baron of Hell and exit. It uses the music track "Collision Course".

Walkthrough
Doomguy starts in a niche at the bottom floor of the main spiral room. Upon revealing himself, Doomguy must immediately kill an onslaught of monsters consisting of mancubi and imps on the floor surrounding a large, sacrifical monument of some sort, and numerous imps, nightmare imps, mancubi, and hell knights around the spiral itself. There is also a hellknight inside a wall cage halfway up the spiral that needs to be dispatched. There is a generous amount of rocket and shotgun shell ammo on the floor along with health and a rocket launcher perched on a vertically oscillating pillar.

One Doomguy scales the spiral and reaches the top, cacodemons and pain elementals will appear. Doomguys best option is to use the BFG, but if energy is not available, the rocket launcher will have to do. There will be a switch on the wall at the top of the spiral that doomguy will have to activate. This opens a niche approximately half way back down the spiral. This niche gives doomguy access to the red door and a teleporter which transports him to another niche where an imp lies in wait. Doomyguy kills the imp and as he passes the open window, a trio of pain elementals appear in the main spiral room which naturally Doomguy kills off. The Doomguy goes through the next teleporter which transports him to the top of the monument where he finds the red skull key, and this triggers the appearance of numerous imps and nightmare imps along the spiral once again.

After Doomguy kills all the imps, he can proceed to open the red door and take out the Baron lying in wait, and finally step on the exit teleporter to end the map.

Bugs
The map has three unused macros and even if whatever object or line cause any of them nothing actually happens:
 * 1) The first macro would raise the ceiling of a sector with tag assigned to 2. Then, after a short delay, lowers floor of that sector along with a sector tagged to 1 to the somewhat far distance down. None of the sectors in the level have these tags, so the purpose of the macro remains unknown.
 * 2) The second instantly lowers a sector with a tag number 3 by 124 units. There is no sector having tag number three in this level. At least, intuitively one cannot guess an apparent purpose of this.
 * 3) Used for spawning things tagged with 5. None of things have this number as a tag data. The fifth tag was likely a typo while original source code of the macro was written.