You're a marine, but in the future. Hmmm... Are you perhaps a... GRUNT?
Future Marine is a Third Encounter scenario by Alan Boyd. I think it's supposed to have a readme file distributed along with it, but my copy simply does not have one, and neither does Dermuda's. I believe that, like GRUNT!, it's only a demo, as it features merely a few small graphics changes and two maps. These floors are rather basic in design, just a few square rooms with secret doors and single-tile passages connecting them. There's not much else to say, the mod's just that simple.
===CREDITS===
Alan Boyd.