Secret Level 1: Asteroid Secret Base
Enemies: Super Hulk, Miniboss, Cloaked Driller, Cloaked Lifter, Platform (Laser), Platform (Missile), PTMC Defense Prototype, Supervisor Robot
Pick up the 3 Shield Boosters and open the door. Carefully take out the Miniboss robot and enter the room. Go up through the tunnel in the roof and pick up the Blue Access Key behind the fan. Head back down and go through the Blue Door. At the room at the bottom of the passage you’ll see the 2 Yellow Doors.
Fly down one of the side passages and take out the robots at the bottom. The Robot Generators will trigger again once you pick up the Yellow Access Key. The roof above the key is a secret that opens up to an area with a Mega Bomb and 3 Shield Boosters. From the grate in the wall you can see the reactor room and take out most of the robots from here.
Head back to the Yellow Doors and go through one of them. Drop down the gap in the floor and follow the tunnel to the left. Make your way through the narrow corridors and down the end below to the right you’ll find the Hostages.
Continue up and around, past the Cloaked Shield. Go up the tunnel and through the door to the right into a dark room. Head down the tunnel at the other side of the room, destroy the robots in the room below and grab the Red Access Key.
Go back the way you came and make a dash for the door on the other side of the dark room before the robots spawn. Continue forwards, out the Blue Door and then through the Red Door.
Reactor: Follow the tunnel to the reactor room. The reactor can be shoot from the entrance to the room. Destroy it and turn around to fly towards the exit.
Exit: Go out through the Red Door, through the next door and then the Blue Door. Turn left to the exit.