I've been inspired by Patrick's example, and have decided to share my thoughts and business results as I proceed with this endeavor. Here's the first earnings report:

I recently uploaded my first game to Kongregate, Urban Defense. It was based on the tutorials, and it was an extremely simple side-scrolling shooter game. There are under 5 minutes of game play. It wasn't just what was covered in the tutorials, though. I found some background music to add to it and also coded some wingmen that will join your main ship and help you fight against the alien invaders.

Since I released the game exclusively on Kongregate.com and I used the Kong API, they share half the ad revenue. My portion came out to $2 for the first day. Since the new games always get a bit more traffic, I suspect the lifetime earnings for this game will be under $10. That's not much, but considering I hadn't ever used flash before and I was able to build the game in 3 days, I don't feel too bad about it. In order to make this a self-sustaining enterprise, I figure I need to get about 14,000 plays a day. That would earn me about $20USD/day and cover my living expenses here in China.

I have two ideas for my next project:

1) Maybe I could do a slightly harder game such as a Tetris or Arkanoid clone.
2) Or, I could make further improvements to Urban Defense, such as a more weapons and levels.

I'm kind of on the fence. I might learn faster from making another game, but I could probably make a more enjoyable one by polishing the one I already have.