From the release:
High atop the peaks of the world, the Star Guild watches the sky. In great choruses the Rock Singers call to the heavens, with the Song of Stars. Their song awakens the spirit of the stars, and draws fragments of starmetal to the earth. In her lifetime a Rock Singer may only ever succeed in calling a few ounces of this precious metal, but with it the guild works wonders.
Occassionally a gnome inventor or miner goes a bit...mad. Lobbing explosive shells and driving over hapless Heroes, these bizzare dungeon bosses bully lesser monsters to collect raw materials for their inventions. This gnomish terror includes treasure, relics, and an extra dose of dungeon mayhem to challenge your adventuring party!