Back when I was doing iOS consulting I wrote and published a few games as side projects - almost got sued by Atari for my version of Battlezone.

Doing something polished as a one man band is incredibly difficult unless you are extremely multi-talented. Sound effects, graphics, music, game design are all skills that you probably don't have.

It is an amazingly fascinating world though and you learn a lot doing it. Just don't expect to become rich or famous!