MAP30: The Gateway of Hell (The Plutonia Experiment)

MAP30: The Gateway to Hell is the thirtieth and final map of The Plutonia Experiment. It uses the music track "The End of DOOM", the music from Doom's text screens.

The Gateway to Hell is one of the three official Doom IWAD levels where the Icon of Sin appears, in this case also protected by a Cyberdemon. This is one of the three levels of Plutonia that contains the same number of monsters and objects regardless of the selected skill level, with the exception of an extra multiplayer-only cube shooter on UV and NM skill levels.

A separate Deathmatch area also exists outside the main map.

Walkthrough
Pick up all the goodies in the starting room (A) and jump down the bloodfall. The bloody floor is not damaging, so feel free to walk on it as you please. Pick up the BFG9000 (B) on a platform in the middle of the room. Go towards the opening in the wall (C). You will be teleported to an area (D) with pillars and Arch-Viles in them - the inner side of Arch-Viles's pillars are floor-damaging, so pick up the goodies inside them rapidly. Go straight forward and the wall in front of you will rise down revealing some Lost Souls. The Gatekeeper is covered and protected by a Cyberdemon (E), which you must kill in order to use the switch on the right. After destroying the Cyberdemon, use then the switch to the left which will lower the pillar (F). Wait until the pillar is nearly at the top and fire a rocket into the the brain of the now unguarded Gatekeeper (G). Fire at least three rockets at the brain, just like in Doom II. The monsters around you may be ignored for the most part.

If any of the spawn shooter cubes spawn a monster at the player's or other monster's coordinates, the player/monster will be killed by means of a telefrag. This will happen even if the player is invincible by means of cheats or power ups.

Congratulations for finishing the entire Doom series! Now it's on to further related games!

Official
There are no official secrets in this level.

Non-official

 * 1) Just like MAP30: Icon of Sin from Doom II and MAP30: Last Call from TNT: Evilution, you can use the idclip noclip cheat code to enter the boss brain area, though it does not count as a secret.
 * 2) Similarly to the "secret" above, you can use the idclip cheat code and look around. After a while, you should find several dark rooms, all containing a weapon of some sort.

Bugs

 * 1) Some items are in the deathmatch area of the map, that cannot be accessed without the idclip cheat: All five berserk packs and one of the three megaspheres. So it is not possible to obtain 100% of the items. Some weapons are affected too: The chainsaw, two of the three shotguns, two of the three super shotguns, all two chainguns, one of the two rocket launchers, one of the two plasma guns and one of the two BFG9000s.
 * 2) If you remain in this level for a long period of time after being detected by the game's boss, this level will fill up with monsters. If many living monsters fill the level, it can cause a possible crash, due to the nature of the Boss Entity that endlessly spawn its spawn shooter cubes that turn into monsters when reaching any given surfaces. The possible crash occurs when the number of living monsters exceed the limitations.
 * 3) In the Deathmatch area, in the lowest part of the automap in the area with the stairs, it is possible to get stuck behind one of the corpses.

Records
The Compet-n records for the map are: