Alien forces have boarded the interstellar
colony ship Marathon. The situation is dire.
As a security officer onboard, it is your duty
to defend the ship and its crew.
Experience the start of Bungie's iconic trilogy
with Marathon. This release is a meticulous conversion
of the original game to the Aleph One engine,
with many details and battles restored that were
missing from the earlier "M1A1" release.
source: ubuntu package description