In Army Corps of Hell, players control a skeletal demon lord of sorts, who is himself in control of a massive horde of goblins. Somewhat reminiscent of Overlord, goblins come in several flavors: Swordsmen, mages and spearmen. Each type can be changed on the fly, and each is suited to a specific need. Sword goblins are the heavy damage-dealers, mages can cast medium-range spells and spearmen can toss spears over large distances. Each type is supposedly suited for different situations, though the swordsman were more than adequate for the entirety of my play session.
My corps of goblins always surrounded their evil leader, constantly accosted by monsters drawn from any number of heavy metal album covers -- one-eyed monstrosities, massive goat demons, you name it. The environment is appropriately hellish as well, replete with dark clouds and floating rock formations. Oh, and the entire game is backed by black metal music, all of which was pulled exclusively from Japanese black metal acts. I think the members of Dethklok would approve.
As I traversed the barren land, I was able to send my minions toward the nearest foe with the press of a button. I watched the swordsman leap on top of it, turning it into a disgusting, vaguely comical pin cushion. Once my horde had completely covered an enemy's body, I could command them to raise their swords and stab down simultaneously -- an action requiring two precisely timed button presses. With the enemy dispatched, I commanded my forces to eat its remains (a giant eyeball) to heal my forces and generally keep things tidy.
After dispatching a few foes, it was time for a boss fight against the aforementioned goat demon. I first had to weaken its legs, causing it to stumble and lower its head into prime stabbing position. After a minute or so, I had lopped off its head (and eaten it, of course), clearing the level and ending my demo.
The overall mechanics of Army Corps of Hell felt a bit simple. For instance, I never really found a reason to use my magic or spear minions, though that could easily be addressed later in the campaign. Regardless, it's hard to deny the fun of slaughtering an enemy and eating its remains, and the promise of local and ad-hoc versus multiplayer is intriguing.