Q: What's the point of this game?
A: Each level is divided into two parts. In the first part, fly around,
   shoot enemies, and collect as many powerups as you can for the second
   part. In the second part, bop around the maze, find the nucleus,
   destroy it, and find your airsled and escape before the fortress
   blows up. After you complete the first eight fortresses, the game
   repeats them again.. the layouts are exactly the same, but the
   warp-tubes take you to different places. Hopefully you've drawn some
   maps; then things'll be easy. You get a proper ending after
   completing this second quest.

Q: Gimme some directions for stage six.
A: From where you enter the fortress -
   - move left, and find the elevator
   - go down the elevator to the small room with two metal hoppers
   - kill the hoppers and enter the elevator in the lower-right corner
   - ride the elevator to the bottom, and walk right until you find
     another elevator
   - go down one floor. follow the corridor to the left and as it curves
     back to the right. allll the way to the right you'll find a warp
     tube on the ceiling, as well as an elevator. the tube leads to your
     airsled.
   - take the elevator down to enter a long, vertical stretch.
   - fall to the bottom, where you'll find an elevator to the right
   - go down and follow the corridor as it goes left
   - walk left to find an elevator. ride it up and you'll enter another
     large vertical shaft. at the top are two warp tubes.
   - take the left tube and you're at the nucleus.

Q: Where the hell is the nucleus at stage 8?
A: .....
   - go down the first elevator and stop at the first floor
   - go left to find another down elevator
   - go down two floors and exit to the right to find a warptube
   - take the tube. you'll go to a corridor extending left
   - go left until you find a down elevator and a warptube on the
     ceiling
   - go down the elevator, and you'll enter a shaft.
   - fall all the way down and you'll see another elevator.
   - ride it down, and you'll see a corridor going right, and another
     elevator.
   - ride up and exit to find a down elevator.
   - ride down one floor, and walk left to find an up elevator.
   - ride it to the top to find a warptube.
   - enter it to get to a long corridor going left.
   - walk left and kill the tank. ride the elevator down at the end of
     the corridor.
   - at an intersecting corridor, go left and you'll see a warptube in
     the ceiling.
   - enter the tube to get to another corridor.
   - go right and enter the warptube in the ceiling. you'll appear in a
     horizontally-divided corridor.
   - fly left along the ceiling and enter the next warptube. you'll
     appear in corridor going left.
   - walk left and enter the elevator at the end of the corridor.
   - ride it up to get to a vertical shaft.
   - fly to the top, to another elevator.
   - enter and ride the elevator. you'll exit to a corridor that goes
     both left and right.
   - walk right until you find a warptube in the ceiling.
   - enter the warp tube to get to another shaft. at the top is the
     nucleus.