Nice concept, but more development would be advised. Still, I got my established goal of 500 points :D.
The sprites are nice, but why the frog always turns to the right when standing? At least, let him stand in the direction it last moved. Also, maybe a working animation would turn out the player's experiment better, just commenting.
For such a huge road, it takes a while to be filled with cars. Although after 100 points, there is a wave of them! So, maybe a little more control on the number of cars would probably be nice!
Nice work!