The Guardian Legend

In The Guardian Legend, the player controls the Guardian of Earth, an "advanced aerobot transformer". The player's task is to infiltrate Naju, a large planet-like object that is being raced towards Earth by aliens. Inside, the player must activate ten safety devices to activate Naju's self-destruct mechanism and destroy the alien world before it reaches Earth. Five hostile tribes of alien life forms are fighting for control of the areas inside Naju, and the player must fight through them to successfully activate the switches and escape.