That's really impressive! Any single thing he is doing by itself is not all that amazing, but combining it all together and producing a very interesting and creative piece of music all alone is pretty amazing.
When I see stuff like this, I usually ask myself if what they are doing would sound better with a whole band. If it would be better with a larger band playing together, then I dismiss it as a show-off and pointless (because for me the music is all that matters, not what any one guy can do). But this was pretty darn cool. It rises above the "can a band do it better" test.