I played the demo too... it has potential...
I like the vehicles, I like the destructable enviornments,
I do not like the shooting mechanics for the regular weapons that you carry, I also dont like how long it takes to kill people.
Maybe I'm just spoiled from playing CoD4 and its such a perfect balanced game. I thought it took too long to kill people with regular guns, and its hard to hit people far away with regular riles and what not as well. I only played the game for one night, maybe I'm not used to the aiming mechanics, but the shooting is much better in CoD4.
The mortar weapon that fires anywhere on the map is perhaps the coolest thing I have ever seen in a video game though.
Its sort of like the hammer of the dawn from GoW, but in first person, from a satelite view in real time.