Nice example of the exponential increase of the speed slider. Quite hard to control in level 7. Once, I lost because the right column was completely filled with blocks, so the door was blocked. Do you always lose if one column is filled or only the right one? I don't know if you want to change that, but I think it would be cool that if one column is filled to the top, a whole row from the bottom is removed (tetris-like). Only if you don't have such a row to remove, you lose.

If you click on instructions and then on back, you start at the beginning of level 1. You could display it as an actor in the current world over all others instead of changing the world. Then pause all other actors until "back" was clicked. In your "sotry", there are some spelling errors. ;)

I guess it would end in a crash or the cars from other side would stop from top speed when the other car drive straight from one side to the other in front of the normal driving car. :D Bicycle riders (who sometimes still crash...) would be killed too because they aren't detected by cars.

I played it now and then for some days, not more than a few hours total I think. Why not playing a good game longer than five minutes? ^^