Soo.... I guess I've been on a map-making roll recently. Imagine that...
Download Retention
Retention is an infection map in the underground section of sandbox. The survivors have holed up in an underground UNSC Factory, hoping to escape the nonsense of the latest zombie Apocalypse (they seem to be happening a lot recently). But, the factory has air vents near the ceiling, and one zombie happens to fall into your little patch of heaven. Oh joy...
Dynamic Features-
1. Safe house that has a switch to open the door
2. Factory tubes that constantly spew out minor weapons
3. Another tube that will rarely spew out a warthog
4. Two office doors that can be sealed by shooting a switch in the middle of the level (offices still accessible from the roof)
5. Automatic lights that turn on 30 seconds into the game
Buildings-
1. The not-so-safe house (human spawn point)
-----Rocket launcher
-----Mauler
-----Assault rifle
-----SMGs
-----Magnums
-----Battle Rifle (roof)
2. Utilities (red)
-----Firebomb Grenades
-----Magnums
-----SMGs
3. Barracks (blue)
-----Battle Rifle
-----Sniper Rifle
-----SMGs
-----Magnums
-----Plasma Grenades
-----Mongoose
4. Two Offices
-----Magnums
5. A Raised Quad
-----Shotgun (top)
-----Grav Lift (bottom)
6. Factory Tubes (four of them)
-----Spikers
-----Grenades
-----Plasma Rifles
-----Warthog (changeable)
Important notes-
-works with most infection game types
-Make sure custom powerup has no use
-If you don't want a warthog to spawn, just select the "mongooses only" option
-Try different strategies/gametypes- it's the end of the world. Have fun!
A pictures worth a thousand words, so here's seven thousand words.
Touch the custom powerup to open the safe house door. This will also take out any idiots standing too close to the door...
Utilities- if you choose to stay here, prepare for some close encounters of the zombie kind. There are a few guns and lots of fire grenades on the roof.
Barracks- You'll have more room to breathe here. Blue is supposed to calm your nerves or something, too. Here be a sniper, a battle rifle, and lots of plasma grenades.
Offices- There are one of these on each side! If you manage to get all of the survivors in these two buildings, shoot the fusion coils in the roof of the quad. This will seal the main door of the offices with a grav lift, but the roof will remain vulnerable.
The Quad- There is a shotgun in the middle of it for the particularly foolhardy. Shoot into the gap in the roof to seal the offices.
Fresh off the Line- There are three weapon tubes (spikers, plasma rifles, and grenades). Use them if you're crossing the factory and find yourself suddenly out of ammunition. The stubby tube spawns the warthog.
The Air Vents- This is where the zombies start. The first zombies actually fall from the surface, but I figured that would get old so all respawns are located where the vent actually fans out.
That's all! I appreciate any suggestions, opinions, or constructive criticism.