Eradicator/Waste Transfer (FBonus)

This level is a fairly small-scale industrial area consisting of quite a few rooms in a complex arrangement. The only objective is to find the exit, but in the process you'll need to find a couple switches to unlock areas.

Exploring
First, go through the level to all the places you can reach and clear out the enemies. This will fill out your automap and familiarize you with the layout. There are two noteworthy areas: the first is a network of channels with brown sludge, and the other is a room at a lower level than the rest of the rooms (referred to below as the "lower room"). Down in the channels you'll find a locked door, plus at one end you'll be able to see up the outflow of a tank into another room that's out of reach. This room is where you're ultimately trying to get to. There's a Geosurvey in the level; get it right away so you can see the rest of the automap. From the lower room, go up the right-hand ramp to the overlooking room next to the sludge channel. You'll see a lift on your right you can use to get out of the channels. At this end of the channel there's a grate on the wall down at the bottom (below the bridge leading out of the overlooking room). There's a secret area inside with a few items including the Geosurvey.

There are two additional secret areas accessible now: both of them are inside big holes in walls. Each of those two L-shaped rooms with the conduits and light-gray texture on the floor has one of them. They don't show on the automap and need to be shot at to get to, but very likely they were blown open while fighting enemies earlier. If they're not, look for the rubble on the floor; they're behind those, plus you can see the powerups inside marked on the automap.

Two switches
From the lower room, go up the left-hand ramp and into the larger overlooking room (not the room near the sludge channel, but the other one). Just to your right inside the following room is a door marked by one of those number placards. Go inside that room (watch out for the pellet bombs the LSDs fire--it's especially easy to get killed here) and flip the switch on the wall. This turns on the lights in the small room past the window in here, and powers the door to that room. Go back to the lower room and take the lift to the overlook and catwalks. The door here goes to that side room (there's another placard on the wall); hit the switch inside. This powers the door down in the sludge channel.

Go down to the channels, to this door; it leads up to the room with the tank and outflow you saw earlier. The level exit is in the next room. Run around in the filled tank and you'll get a Li'l Buddy and some other items. (It's possible to use Low-Grav Boots to jump up the outflow of the tank and into this room and exit as soon as you get to the channel, but you're missing out on a good level if you do this.) When you're done, go to the side room and exit the level to continue your mission.