MAP22: Habitat (TNT: Evilution)

MAP22: Habitat is the twenty-second map of TNT: Evilution. It was designed by Christopher Buteau and uses the music track "AimShootKill" by Tom Mustaine.

Overview
This is one of the few levels in TNT: Evilution (the others being MAP04: Wormhole and, if you are using a source port that allows to jump, a few more maps) that don't require any of the three keys to be finished.

Essentials
Kill the gunners behind the crates, then find an alcove leading to a pool of nukage and drop into it. Walk up to the center of the silver round wall at the opposite end to lower it. Continue forward to another lift and lower it. Grab the berserk pack and the invulnerability power-up and you'll enter a huge hill-like area. Cross the river and go inside the structure on the other side, revealing the exit pit. And that's it.

However, there are many places that you have to explore in order to get 100% of everything (and the three keys).

The trap on the hill and the blue key
From the start follow the river in front of you until you come to a hill. Walk towards a big wooden door and it will open by itself, revealing a tough trap. Behind a fake wall is the blue key.

The tunnels
From the start find a spot where the slime intersects with the water: if you follow that path, you'll discover a pit. Open a wall and you'll enter a complicated system of winding tunnels. To discover everything, read the section about the secrets.

The blue door, the sign of evil and the yellow key
In the south-eastern area of the tunnels is a giant blue door. It leads to an area with the yellow key. When you grab it, the room will turn dark, except for a glowing sign of a star in the center (the sign of evil) where enemies will teleport.

The yellow bars and the short cut to the slime pit
In a corridor in the tunnels which is accessible through a secret wall are some yellow bars: they will just take you to the slime pit with the "L"-shaped ledge.



Secrets

 * 1) Walk straight through the wall directly behind you at the start of the level to access a short hallway leading to a soul sphere.
 * 2) Picking up the soul sphere in secret 1 registers a second secret.
 * 3) After picking up the soul sphere in secret 2, the large crate in the starting area lowers for a short time, revealing a switch. Flip the switch before the crate raises again and a hole will open in the corner. Drop into the hole to get the BFG 9000 and Rocket Launcher.
 * 4) When entering the tunnel, you will hear a door open. Return to the previous room and get the now-accessible chainsaw. The room that opens upon picking it up is tagged as secret.
 * 5) Once inside the tunnel, follow it to the east until you reach a fork. Go right, then left, and then straight through the next intersection. A wall will open up to the left just ahead of you. Go through this green hallway (A) and follow it to the end, where you'll arrive in the main tunnel system again. Once in the main tunnel, go right, and the wall in front of you will open. Continue through this second green hallway (B) until you see a narrow passage in the left wall. There are some health bonuses inside.
 * 6) Inside secret 5, there is one wall that stops just before reaching the floor. Walk straight through it. A lift with a red skull key on it is inside; it is triggered by entering secret 5.
 * 7) On the opposite side of secret 5 is a third green hallway (C). If you entered hallway A, a connector will have opened between hallway C and a fourth green hallway (D). There are several armor bonuses and a yellow door in hallway D, though the connector itself is tagged as secret.
 * 8) Exit green hallway C through the eastern entrance. This opens another secret connector between hallways A and B.
 * 9) Behind the level exit is a red door. If you got the red skull key in secret 6, open it and step through the teleporter to be taken to the bottom of the exit pit. Get the combat armor and go back through the teleporter, which triggers this secret.

Warning
If the level is played with the -respawn parameter set, there is a higher than normal chance that the moving platforms limit could be exceeded on this map than many others. This is on account of the respawning monsters continuously activating the large amount of floor-lowering linedefs in the tunnels.

Routes and tricks
It will take quite some time to complete this level under UV max rules, as all of the enemies and all nine secrets are spread throughout the entire map, which is quite large in size. You cannot leave any of the long, winding tunnels in the east unchecked, for all of them are filled with hellspawn, and some of the secrets are located there.

On the other hand, under UV speed and NM speed rules, this level is one of the easiest in Evilution to finish. As you take the normal path through the level, you raise an L-shaped platform in the giant slime pit; walking across its western end causes the western pillar to lower, leading to an elevator up into the final area of the level. However, due to the way the Doom engine works, the walkover linedef that lowers the pillar can be triggered before the platform is raised. Through this shortcut, the level can be completed in under 20 seconds. It is also very easy to finish this level under UV pacifist rules with this route, as you face very little opposition on your way to the exit, and the few monsters you encounter on this route (the Spectres at the top of the western elevator) are easy to avoid, as long as you awaken them by firing a shot with any weapon while waiting for the elevator to come down. This will cause them to move away from the location you arrive in, and then you can run past them to the exit. Consequently, all of the UV speed demos of this level are also UV pacifist runs.

It is difficult to successfully record a demo on this map with respawning monsters, especially NM100S demos, without the game crashing, as respawning monsters can cause the moving platforms limit to be exceeded (see the warning above.)

You don't need any keys to exit the level, all you need to do is simply walk into the exiting circle. This way, you will not have to explore the tunnels at all.

Records
The Compet-N records for the map are: