Really, the game plays a lot like Pikmin. You play as an evil Overlord intent on destroying the Seven Heroe that killed your predecessor. Now, as a standard villan, you don't want to do the hard labor yourself. You can control up to 50 Pikmi- I mean minions. They can attack enemies and move heavy objects out of the way or carry them back to the Spaceshi- I mean Tower.
Now, the Overlord is no Olimar. Olimar could punch, but wasn't that great in combat. The Overlord, however, in standard evil villain fashion, is clad in dark armor with an axe that can feasibly swung to do some pain personally. Also, he's got some magic spells. In the demo I saw, the only one available was the fireball. Interestingly, fields of grass are flammable, and the fireball clears all of it quickly - along with any critters in it. The game looked great and ran smoothly at ~60 fps on my friend's 360, but he and I couldn't help but laugh at how much it was like Pikmin.
Also, while you're suppost to be an evildoer, the quests in the demo had you HELP a peasant village by rescuing some of their kinsman from evil halflings. This is unacceptable! I wanna be a jerk! I wanna rescue the people so they hail me as a hero and invite me for a feast, then wait until everyone is dead drunk and kill them all!