I have a demo. You die somewhat haphazardly when objects collide, and it doesn’t tell you when you win (but you have when all the blue thingies have reached the opposite side). I do have win detection, it just doesn’t show anything. What else… Ah, you place roads by clicking the gray tile in the toolbox and then clicking in the world. Roads make objects go twice as fast. Restart the game by clicking [R].

Demo

I’m afraid I won’t be able to add a lot of maps though… I’m aiming to do this in under 4kb (so I can submit the game to the Java4k competition as well), and I’m almost out of space.

Screenie, in case you can’t try the demo: