WMG / Daemon X Machina

The game takes place on Mars, and is a distant prequel to Armored Core 2 (Major Spoilers!)

The continent the game takes place on looks a lot like Eurasia, but it's different in many ways. For example, the British Isles are now a peninsula connected to the mainland by France, and Africa is nowhere to be seen on the lower-left. Now, obviously the Moonfall would have caused some major geographical upheavals, but the "Life's Purpose" ending has humanity migrate to a planet that looks exactly like Earth, continents and all, while implying that it's in the same star system as this game's "Earth." Armored Core 2 has humans colonizing Mars and discovering ancient technology that greatly resembles the Dominator and the Immortals, called Disorder Units in that game. The Final Boss even grafts himself onto an alien mech found on one of Mars' moons, just like Grief does. This theory posits that Mars used to have a single moon like Earth does, which broke up during the Moonfall and would eventually continue decaying, splitting into Deimos and Phobos after humanity left but still containing all the Dominator's tech inside. By the time humans return to Mars, they've completely forgotten that it used to be their homeworld and end up rediscovering the Dominator's technology all over again.