At first I was thinking "this isn't a big deal, Atari Jaguar CD did this back in 1995 on way less hardware," but then I realised it was a hackathon project and now I'm really impressed at how far they got in that short frame of time!
Pretty boring if it's just FFT based. I'd love to see music visualizations make use of more sophisticated musical feature detection, like polyphonic note recognition or tempo/rhythm analysis.