Solar Sailor is starting to take shape... very very slowly. This is what it looks like now:
Doesn't look much different from the first screenshot I posted, does it? Fortunately now there are some proper game mechanics going under the hood: the blue balls are racers, the brown balls are obstacles and I'm simulating the effects of gravity on all the racers. You can control one of the blue balls with the WSAD keys.
I can't honestly call it a game yet because there are no win or loss conditions, or anything remotely resembling a challenge. But it's getting there.