In the 21st Century, humanity has colonized the moon and uses lunar workers to mine rocks and minerals for transport back to Earth. Some of these Lunarians though are fed up with the living conditions, hard work and the fact that they are not allowed to return to Earth. A group of rebels decides to revolt against Earth rule, and a terrorist campaign begins in the domed lunar cities. Shun Nonomura, a young lunarian and brother of a famous rebel, must now decide whether to join the revolution.
Meanwhile, a strange ruined alien machine called Dallos - worshiped as a god by the Lunarians- sits silently buried in the lunar surface and waits for something - or someone - to bring it back to life....
- Artificial Out Doors Display: The lunar colony has a simulated blue sky overhead despite being underground. The mines seem to be the only exceptions.
- Big Dumb Object: Dallos. Nobody truly knows who built it and why. By the end of the OVA, we're left with more questions than answers.
- Les Collaborateurs: A Gray-and-Grey Morality version. The first-generation and second-generation lunar colonists are conflicted about their feelings for Earth, which they still see as their homeland. In the end, they go back to work for the Earth, leaving the third generation to continue the fight.
- Deus ex Machina: The Earth's military is about to crush Dog's guerrillas, and then Dallos destroys both sides, temporarily forcing a truce in the conflict.
- Generational Saga: One of the major themes of the OVA is exploring the disconnect between the three generations. In a deviation from the usual sequence, it's the third generation who represent the fully-assimilated Lunarian culture, who have never seen Earth and have no loyalty to it; the second generation still think of Earth as their home.
- Lost Technology: The colonists think Dallos is this, since they believe it was built by human scientists in the early days of lunar exploration. The possibility that it could have been built by aliens is never considered.
- Machine Worship: The lunar colonists worship Dallos as their god.
- No Ending: The series ends where another series might begin. Shun and Rachel have been radicalized and join Dog's crew, the Earth refuses to make concessions, and Dallos' eyes are glowing green, but it's unclear what any of that means or who will win. The story isn't about the war or about Dallos, anyway, but how they affect people's lives.
- Powered Armor: The labor exoskeletons repurposed by Dog's crew for the fighting, and later the military exosuits used by the Earth forces.
- Remember the Alamo: "Remember Bartholomew!"
- Riddle for the Ages: What exactly is the deal with Dallos? Who made it, and why?
- Sequel Hook: The end credits of episode 4 show a number of things indicating a longer story. Melinda returns to Earth to reveal the truth about the suffering of the colonists. Dog and Shun prepare their forces to fight again. Dallos' eyes glow green as it starts up again. Interestingly enough, the anime was originally meant to be a full TV series but was cut down to 4 OVA episodes and a movie compilation. The images in the end credits seem to support this.