I recently started to use the Game Boy (DMG model) with the latest Nanoloop in our live gigs. We have one piece that is an improvisation for Game Boy and bass clarinet, which I think is quite fun. I program the whole sequence live from scratch on Nanoloop and my mate is playing the clarinet on it. In second half we also add some beats (curtesy of the LXR drum synth) and some loops I record from a bent Casio SK-1.
Here's a video of the last live performance we did: https://www.youtube.com/watch?v=85tb_hximnY
and just because I have it at hand, a pic from the performance: