I played the demo a bunch of times at my friends. It's a lot of fun, I mainly enjoy the free roaming side of it. I didn't really try to finish any missions. I like riding on top of cars while shooting passing drivers in the face, then strapping a pedestrian to the roof of a passing car and watching them fly through the air and get dragged along the road.
It's also a lot of fun riding on the roof of a car and strapping two cars moving in opposite directions together and watching them slingshot off the road.
It's also a lot of fun strapping enemies to rockets and firing them into the sky.
It's also fun riding on the roof of a plane like a surfboard and then jumping into a nearby helicopter.