Level 9: Mars Military Dig
Enemies: Class 1 Drone, Medium Hulk, Super Hulk, Advanced Lifter, Secondary Lifter, Cloaked Lifter, Spider Processing Robot, Baby Spider, Driller
When you fly forwards two secret passages will open behind you, releasing a bunch of robots. Turn around and take them out before continuing. This level is composed mainliy of narrow, winding hallways. Try not to get snuck up on by roaming robots.
To get to both the Blue Access Key and the Hostages follow the lower path by the lava. Find the gap in the floor and drop down into a chamber with a Robot Generator. Take out the robots, free the hostages and grab the key.
Head back up and go through the Blue Door. Around the back of the grate you’ll find the Yellow Access Key. The wall to the left of the grate is a secret door that leads to the second lot of Hostages.
When you find the Yellow Door go through but as soon as you enter the sides will open and robots will fire at you. Grab the Red Access Key and make your way around to the Red Door. Go through and fly up to clear out the path to the exit. Fly back down to the reactor.
Reactor: After going through the Red Door, drop down, take out the Medium Hulks and destroy the reactor.
Exit: Fly up through the door in the roof, up through the Red Door and follow the tunnel around. Take the next right to find the exit.