A #1 iPhone game-app dev says: Don't expect to make a living from the AppStore
macworld.com
macworld.com
Spend some time on game design quality!
I'm not trying to make a moral judgment, just adding some info you may not have. The game is not original.
If you're going to steal a mechanic (most mechanics aren't entirely original anyhow), take the time to spin it into a new context.
http://www.rocksolidarcade.com/games/stuntpilot/ http://www.squiddlegames.com/stuntpilot/
I'd like to note that I actually hadn't played any game like Stunt Pilot when I wrote it, although I've since played Pilot Wings. Stunt Pilot was designed to be a playable version of air racing.
"...but too much is left up to chance for a one-man development shop to earn a steady living."
The iPhone hardware and its built in apps set a certain level of expectation of polish. Graphics that would work on other environments won't cut it on this device, especially when there are a lot more options.
"I had a hit! I coulda been a contendah!" ;-)
I think the whole world now knows that, if you build something good & it goes viral, you can make a lot of money for a while. Then, with the app store churn, if you don't get and stay in the top 10-25 app charts, and don't do serious promotion, your app is almost guaranteed to fade away.