If you have followed the red carpet, you'll stand in front of these two force field doors. Open the right door, shoot the roof, and a secret door opens.

A few steps further you get to the big room, with the explosion vents high up. Don't stand in this doorway and admire the wiev - get across and jump overboard. Beware of lava. You'll get a secret plus safe passage.

Related to #2 - if you go a level further up, right in front of the explosion vents, there is a hole in the floor. Jump in and take goodies. It gets funny when you get out - that happens right in front of the four guns from #2! Haul ass, soldier!

Taking the back door into the level, you arrive at a shaft with a railing and a lift. Go down the shaft. First, if you stand in front of the lift for a little while, a hole appears in the roof. At the top of the hole is a giveaway button. Shoot it, and a goodie pops out.

Go past the door - the yellow field has to be off first. Right over the acid pool is a wall. Shoot it for the next secret.

At the back of the pool is a tiny stone. Push it, it's a switch that opens a door under the acid surface. Don a environment suit and jump in. To get out again, shoot the wall opposite the main 'goodie'.

At the top of the big service lift is a pair of small sliding doors. At the ladder side, shoot in the dark corner, and you have the last secret.