Level 19: Oberon Mine
Enemies: Small Hulk, Medium Hulk, Super Hulk, Medium Lifter, Cloaked Lifter, Driller, Heavy Driller, Platform (Missile)
This level is designed in such a way that the Exit is at the top with a tunnel leading down through the Blue and Red Doors. Concentric circles around the outskirts with roaming robots makes this a fairly difficult mission. The ring is composed of four quadrants with a room in each quarter. One of them will have the Hostages.
Once you’ve cleared out the inner area take the door in the outer ring. Make a dash through the hallway, with Heavy Drillers on the outside and into the room with the Blue Access Key. Make your way back to the center and through the Blue Door.
Once again as soon as you enter the area you’ll be attacked by multiple robots. You may want to use Smart Missiles to clear out some of the enemies. This section is a little harder to navigate with all of the little passages. Around here you’ll find the Energy Center and the Yellow Access Key is in the room with all the Heavy Drillers.
Go through the Yellow Door and navigate around the small passages until you find the Red Access Key. Around these passages you’ll also find the second set of Hostages.
Reactor: The reactor is underneath a platform when you go through the Red Door. There are Heavy Drillers on either side. Around the back there’s a Super Hulk. Take them out and then destroy the Reactor.
Exit: Straight up through the center of the mine.