The combat interface is pretty straightforward and intuitive. As your character mauls more and more of the hordes that are thrown at you, and I do mean hordes - there are tons of enemies onscreen at once, their ability to do a special move hits a peak and can be executed. If all three characters are at that level the entire party can do a special attack via the R3 (pushing down on the right analog stick) that's called a super move. The most problematic elements of the combat are simple in nature, namely that the AI that guides the two characters that you aren't controlling is less than intelligent and cannot be modified. They seem to be primarily defensive and only interested in protecting themselves. It would've been nice if behavioral elements would've been implemented here in that you can modify the risk/reward ratio of particular characters from being passive to being overly aggressive. Also, it makes one scratch their heads why there isn't two-player cooperative play in this title, a la Lord of the Rings: The Two Towers.
Demon Stone, by its very nature, is screaming for two or more players to battle it out against waves and waves of enemies. Finally, the camera gets very wonky at times and you'll find that you'll be trying to look around enemies that are in front of you to even see your character at all. This is particularly evident when battling the monstrous spider in level 5, where you'll need to defend with your sorcerer, charge his staff, and try to get a shot off before the spider sends his poisonous spout your way. While it's moderately frustrating, it wasn't a terribly big detraction in the overall scheme of things.
The game is also woefully short. An experienced hack and slash player should breeze through this thing in under 12 hours and even shorter than that on the lower difficulty setting, which leaves one wanting for much, much more. The short experience, however, is one that is worth traveling through, especially if Lord of the Rings: The Two Towers is appealing to you. This title is a graphical powerhouse that can have over a dozen enemies surrounding you and it never seems to chug. The cinematic in-game presentation leaves one feeling as if he had just hacked and slashed through an actual film. Maybe he did and maybe you should.