Duke was sent to an EDF base in the orbit of Earth, called "YMF500G" and while he was doing a test mission the base was attacked by aliens, so they disconnected the radio systems and killed all the people in the base. So, Duke must reconnect the communication systems to get help from Earth.
Galbadia is a single-player modern style city map for Duke Nukem 3D which involved 4 mappers.
Duke is sent to Galbadia to investigate claims of a secret alien hive nearby, the purpose of which is believed to be using captured local babes to breed alien drones. Duke rents an apartment near the central park and takes a shit. Upon learning of Duke's presence, the hive Overlord commands his troops to seize the town as a means to protect the hive. Next thing you know, you've got Recon Cars circling the park while an alien breach squad is on its way to your apartment. Your task is to locate the hive and kill the Overlord.
The intelligence services have discovered an alien base in the underground of the city, and they have found out that this group of extraterrestrials of the faction of leader Edward, better known as Eddie, they are preparing a worldwide attack on the earth. Duke is the last hope Humanity must destroy that underground base.
Another day, another city overrun by the alien hordes. You start in an apartment, lightly armed, and as you look out the window, you not only get to enjoy some enemies trying to plug you full of holes, you get to enjoy an incredible view.
After learning the location of the alien homeworld. Duke is drawn off course by a distress call from Cerberus station, an enormous deep space platform watching over a nearby darkmatter nebula. His ship is ambushed by several alien fighters which he destroys but at a heavy cost. He must now dock with Cerberus both to find out what happened to it and repair his ship (or secure another one).
You're in Fernocity, the most corrupt city in the world. A level with loads of action, and lots of places to explore: A pier, a strip club, an abandoned power plant, an arcade store, a bank, and even a haunted apartment building! And much, much more!