More importantly, Firefly wants to use that setting to explore the whole idea of an underground world. The "dungeons" in the game are subterranean cities, living and breathing, in which the goblins live, work and fight. This is the dungeon from the point of view of goblins - not just somewhere for heroes to invade and nick treasure from, but actually a place where a whole species makes its home.
The upshot of this is that goblins actually become characters rather than brainless monsters. The Firefly team professes to be sick of games where you find a goblin, orc or whatever patrolling a room, with a Level 5 Giant Spider standing three feet away (but not attacking the goblin, for no apparent reason) and a conspicuous chest in the corner with a Helmet of Pith or whatever inside it. In a realistic fantasy world, this just wouldn't happen. It breaks the fiction. In the brief section we saw, Firefly's counter-point to this expressed itself pretty clearly.
You're recruited by the goblins to fight in a battle against their enemies, another goblin tribe who reside in a city across a stretch of desert that has become a battlefield - and rather than showing us the goblin home city, Goldstar, the developers decided to show off a zone called the Back Trenches. These are the tunnels which lead from Goldstar up to the battlefield - and as such, they're filled goblin soldiers who are off-duty and waiting to return to the fray, as well as the wounded and the dying who have been stretchered off the field. It looks and feels like a World War I scenario.
