I really like the idea for this game as a fast-paced multiplayer vehicle battle game. The sound and the graphics also fit very well. I think the gameplay still needs some work, as it is pretty difficult in the beginning to get a feeling for the driving. I think it needs some tweaking of the parameters, so that it feels that you are really driving a vehicle. Not sure if you have it already in, but some physics system with proper acceleration, friction, etc. would help. I was not so sure about the multiplayer aspect... It did not look like I was playing against humans and rather AI. I think you should make this obvious and offer two game modes: One against AI and one against real humans.
Still I like the idea and I think this is a pretty solid entry which might just need a bit of tweaking.