I'm in my late 30's and have been teaching myself how to play the piano for the past year and a half. I started off by buying an electric piano (a Yamaha P-155) and some Super Mario Bros. sheet music. My reasoning was I know all of the songs and Konji Kondo's work got more complex when he was composing for progressively more capable consoles.

I absolutely sucked donkeys at first. Even the 8-bit Super Mario theme song is pretty difficult when you're trying to read sheet music for the first time. It was pretty embarrassing, but I've stuck with it and try to play for at least 20-30 minutes a day. I also try to play on any piano I can find, and also try to play for anyone who will listen, just so that I get practice playing in front of people. That was actually remarkably difficult at first; my hands were literally shaking as I tried to plonk out a song. But, it's like anything. If you keep doing it you get better and better.

Here's the link to the sheet music: http://www.amazon.com/Super-Mario-Series-Piano-Easy/dp/07390...

I (somewhat recently) taught myself how to play the piano solely by playing Mario songs. There's a pretty decent easy piano book which goes through the entire canon.

Here's a link to the book on Amazon: http://www.amazon.com/Super-Mario-Series-Piano-Easy/dp/07390...