This new version changes all that. JS is a thousand times easier to work with, and I can make it run on any browser that supports the <canvas> element. Point of fact, I even added special touch controls for phones and tablets. I also added a high score tracker (using localStorage), the ability to pause the game, and new obstacles. There are also some options now, like car color, or special cheats for testing. Oh, and as a side effect of using the canvas it now scales if you want to zoom the page in. Unfortunately this makes the pixel art look like crap since most browsers don't support scaling styles on the <canvas> yet - but it's still nice if you find it to be too small.
I also revamped the score keeping and game balance. Now your score increase is tied to time, and not affected by speed. Your score will still get a bonus for close calls, and now there is also a bonus for avoiding direction changes to reward more skillful players. On the flip side speed is also no longer tied to the score, meaning the rate of acceleration is constant. This also means that I fixed the bug where well timed invocation of the close call bonus let you avoid increasing speed. The acceleration is a lot smoother now too, instead of jumping substantially every thousand points it now slowly increases over time (the actual acceleration is about the same, but over a longer period). The end result is actually a lot harder, as in you can't score nearly as high as you could in the Java version.
For a slightly better experience try it on its dedicated page.