A great start.
The graphics, sound, etc. are very poor, but you did manage to make it actually pretty fun. There were a few waves that were a little intense to dodge.
I would spend more time on graphics and sound, try to make the waves of cars less defined, up the framerate a tad, and up the difficulty a ton.
Also, I love the title screen. Looks great!
So while it was surprisingly fun, you really gotta up the cosmetic quality, add some variety, and tighten up the gameplay.