MAP03: Manufacturing Plant is the third map of Mars War by Nathan Lineback. It uses a MIDI conversion of the second tracker module which plays in the demo "Buttman: The Terminated" by the Norwegian demoscene group Twilight Zone.
At the start of the level, there is a megaarmor on top of a crate in the northwest. Push this crate to obtain the megaarmor, as well as a medikit and a plasma gun hidden behind it. (sector 141)
In the passageway overlooking the cavern, press on the computer controls at the north to find a computer area map. (sector 121)
At the other side of the chasm, there is a switch in the southeast. Activate it, and quickly run back into the passageway overlooking the cavern to find that part of the railing has lowered, allowing you to jump into the cavern, and find a stimpack, a medikit, two health bonuses, one armor bonus, two clips, 4 shotgun shells, and an energy cell. (sector 126) In the same area is a lift with a supercharge floating over it; activate the lift to obtain it. To escape this secret, activate the lift in the northwest of the room.
In the wooden hall leading to the yellow door, enter the southeast room to find that part of it is blocked off by a wide crate. Use the crates in front of it to climb onto it, drop down, and then open the nearby door. After this, press on either of the two demon heads at the south to find three health bonuses, three armor bonuses, a berserk, a box of rockets, and a rocket launcher. (sector 163) Upon entering this secret, the wide crate will sink into the ground, allowing you to exit this secret.