Really brilliant design! It took me a while to get the hang of things and not accidentally jump into the void, since sometimes W was up and sometimes it was jump. I did get to the point of being able to move and switch perspectives at the same time, rounding corners like a proper citizen of three dimensional environments.
The look is great, the mechanics are phenomenal. The main character is a little too chatty. The ending was fabulous; after the pipes I, too, was ready to surrender myself to the embrace of the labyrinth.
Different music for different levels would have been nice, but as you made it yourself I can't complain about the variety.