While learning pico8 for use in an upcoming game jam, I implemented a single-button control scheme for a platformer character. It was so fun to see how many different actions I could squeeze into a single button. I fleshed it out with as many screens of level as I could squeeze into pico8's tiny constraints, and polished it as well as I could.
It certainly has a bit of a learning curve, but I think it turned out pretty well all things considered. The entire project took about three weeks, including code, pixel art, and music. I'm really pleased with pico8's built-in editor and some smart choices in the music tracker. It's limited, but the tools I really needed are all in there.
Enjoy!