4 What About Bob?

Tips

Don't forget to grab the weapons and ammo located 'around the back' of the central structure in the room that you start in.

After you drop down the shaft, you'll be in a pretty tough situation with two of the tank guys and several Pfhor on your tail. Instead of trying to face them, it would be best to run laps around the room to get the aliens to fight themselves. Once enough of them are killed, then move in for the kill. In generally let the tank guys kill each other off by continually moving around in front of two or more of them.

When you enter the lava rooms, aliens will be crossing a thin bridge to get at you. Instead of shooting at them straight on, fire a few grenades from an angle. This will either kill them, or knock them into the lava, which effectively kills them as well. If you get swamped here, back up into room with the ledge and stairwell. Stay on the ledge, wait until the aliens have past the stairs, then jump to the stairwell and flee to the recharge panel in the middle of the lava pools.

As Durandal says, disable the first control panel first, then the second, otherwise, getting out will be way too difficult.

In the last half of the level, you need to make sure that you clear out all the sections. This simply requires you to enter the room to get the bob's to teleport in. You can then retreat and let the BOBs have at it. You won't be able to leave the level until you do this.

Secrets

After hitting the second lava switch, if you turn to the left, there is a passage that opens and runs to an elevator, which will take you out of the rising lava, and to a nice little ammo stash. However, you need to be quick and at full shields to succeed.