As much as I want to stop playing until the full version comes out, I just can't help myself! So many fun/satisfying/amazing things happen every time I play the demo, largely due to the excellent use of Havok.
While wandering around, I came upon a near head-on fender bender, and a pedestrian that had been knocked to the ground during the collision. He stood up, walked up between the cars, and started making threats: "You better believe the police are going to hear about... " Right then, both vehicles involved in the fender bender peel out and take off in the same direction, pinning the pedestrian between them and cutting off his sentence with a guttural grunt. They made it about half a block away with the poor guy's arms and legs sticking out and flailing around before they separated, releasing the pedestrian to skid and bounce along the pavement, killing him.
In another situation, I blasted a stopped van with the shotgun, setting it on fire. The car behind him freaks out, quickly backs up, and tries to speed past the burning van. The van explodes when the fleeing car is right next to it, but the car doesn't explode - it gets sent skidding sideways on two wheels right towards me, with the driver (killed by the blast) dangling out the window with his arms and head dragging on the ground. The car comes to rest right in front of me, where the driver finally slides out of the window and flops onto the street. It was so incredibly satisfying and cinematic that it couldn't have been planned any better... and this is just the demo!
I still have my doubts about the story, humor and overall tone, but the gameplay is more fun than I could have hoped. If co-op wasn't restricted to structured missions, this could have been one of the greatest 2-player games ever.