Just seeing a post and pile of code about a project isn’t always that interesting. The nifty thing about this project is also one of the problems. They’re cosmetically identical – so you can only tell which one you’ve got by activating it. :)
I couldn’t be more pleased with the way this project came out. I basically took my daughter’s setup based off an Adafruit Circuit Playground, built a more specialized (and louder!) version into a breadboard using an Adafruit Trinket, and then ported the entire design into an ATTiny85. The only thing I would change about it would be to add a socket for the ATTiny to make it easier to modify down the line.