Invasion... Level 2: The Upper Decks

Invasion... Level 2: The Upper Decks is a single-level PWAD for Doom that was released in 1994. It was designed by Andy Chen and Claude Martins. It was preceded by Invasion... Level 1: Contamination.

Invasion... Level 2: The Upper Decks was featured in Doomworld's Top 100 Most Memorable Maps, placing 83rd.

Secrets

 * 1) In the south-east of the room surrounding the room with the switch that opens up the door to the exit is a secret door leading to a shotgun. (sector 90)
 * 2) The east wall of #1 is fake - walking through it leads to a room with a door. (secret 1012)
 * 3) Go through the door in #2 - you will reach a room with some medikits, some ammo, and an armor (two on multiplayer). (sector 1014)
 * 4) Go west from the crossroads just west of the area from which #1 is accessed and go north through the yellow door.  There is a secret door on the west side (marked with a misaligned texture) leading via a lift to a dark room with a switch on its south wall. (sector 306)
 * 5) The switch in #4 raises another switch in the same room as the ones that open up the locked doors in the eastern room.  This switch opens up several further secrets.  One of them is a room in the southern part of the corridor leading north-east out of the south-westernmost area (the part the bridges travel over).  This room contains two imps (three in mulitplayer) and some ammo. (sector 981)
 * 6) From #5, head along the corridor to the north then take the door that leads north then west.  The switch in #4 has opened up two secret areas opposite each other, each containing some imps, two armor bonuses, a medikit, a box of bullets (medium and hard skills only), and a box of shotgun shells (hard skill only).  (sector 970)
 * 7) See #6. (sector 983)
 * 8) #6 contains a switch which lowers a platform passed en route, containing a soul sphere, a light amplification visor, and a megaarmor. (sector 963)
 * 9) Just west of the exit room is a path leading north via several doors and switches to a large pink-floored room, at the western end of which are a megaarmor, a soul sphere, and an invulnerability.  Approaching these raises some steps, allowing them to be obtained.  The sector between the two short red pillars counts as a secret. (sector 1083)
 * 10) Continue further along the corridor from which #4 is accessed.  Just before the T-junction is a fake wall leading to a room with some imps, a stimpack and a partial invisibility. (sector 1174)
 * 11) The corridor containing #5 has a fake wall to the east leading to a room with some imps, a stimpack, and a medikit. (sector 1179).

Current records
The records for the map at the Doomed Speed Demos Archive are:

Player spawns
This level contains twelve spawn points:
 * 1) facing north-west. (thing 3)
 * 2) facing north. (thing 4)
 * 3) facing east. (thing 5)
 * 4) facing north-east. (thing 71)
 * 5) facing south-west. (thing 562)
 * 6) facing north. (thing 563)
 * 7) facing west. (thing 564)
 * 8) facing north-west. (thing 565)
 * 9) facing south-east. (thing 566)
 * 10) facing west. (thing 705)
 * 11) facing north-east. (thing 713)
 * 12) facing north. (thing 714)

Things
This level contains the following numbers of things per skill level: