Here's a very cool and playable game project being developed by "martinsh".
...[I] just finished this game at my spare time. This is very similar to my motocross sidescroller game. [The] goal is to get to [the]track's other side.
Up/Down: drive forward/brake
Left/Right: torque chassis to left/right
Q/A: resize back wheel
W/S: resize front wheel
(hint: resizing the wheels helps when you get stuck)
martinsh also suggests:
...need to make more tracks.
Feel free to edit and make your own tracks.