I just received an Adafruit Circuit Playground, and have to say that it is really awesome… although not quite as awesome as this project! It was designed to use to teach programming, so has a lot of sensors (temp, light, mic, accel, 2 buttons, switch), 10 neopixels (same as the RGB leds on this project), piezo speaker, and the pins/pads are already setup to do touch sensing (like the Makey Makey banana piano).
Takes away some of the confusion and parts sourcing of wiring up sensors to an Arduino board, you can use multiple languages on it (Arduino, Python, ?), and it is only $20.
I have been messing around with learning microcontroller programming coming from the artist side of the equation, and of the boards I have used (arduino, trinket, pro trinket, gemma, flora, lilypad) this has been the easiest to get working. Since it is being setup to be used in education, ground up tutorials are being written for it, which will hopefully not gloss over pertinent bits of knowledge because of expert blindspot ;p