I was a little tired last night, so I didn't get too terribly far, but I did get what I wanted to get done out of the way. It's finally interactive, which begins its seperation from just beign a technology demo to becoming a full-fledged game. There's still a lot I want to put into this game, and some inevitable tweaking will be done, but the engine is pretty well there. Now for such things as scoring, levels, and "Game Over" screens, as well as some form of title screen / attract mode.
I ran into an issue with how I was doing the spraying, but I think my "work-around" looks even better than I had hoped.