A portal 2 mod set on the moon (Or more specifically inside the moon) Aperture hollowed out a lot of the moon during the space-race and made testing facilities in the hollowed out rock which was later re-purposed for mining moonrock for gel. You are awoken from slumber in a relaxation pod years in to the future when the underground facilities are crumbling and close to collapse. Find a way to the surface and back to earth..
Nothing shown is 100% guaranteed to be in final build.
Those kinda look like arcade machines.