I got much more into this on my first play than I thought I would. I think you did a really good job on the difficulty curve. You start out nice and slow, learn how the mechanics work, and then the amount of cars start to creep in, and then suddenly they start crashing into each other (Which I really wasn't expecting at all, was pretty great and kept me engaged for a while longer).
The high score page doesn't seem to be giving me my score, just takes me to the "game over" screen.
I also think I've developed a real winning strategy here -- using the big trucks as shields!
