Hi!
I'm glad you've been inspired to try your hand at making your own Genesis game with SGDK!
I've just uploaded the source code of the game here on the itch.io page (see download section). The code is heavily commented, but as it was made in 60 minutes it's not an example of "best coding practice" ;). The game is simple so the code is short though, so I hope it'll be helpful to you!
Don't hesitate to ask me if you have question about the code or need anything else!