I seem to be working my way up the right-hand-side of the “level select” screen. I don’t know if this a because I’m doing well, or doing poorly, but I suspect the latter as it’s a bit bloody hard.
I can’t do the second Sound Slalom level (which is the fourth level so far), and the level previous was really quite difficult. The best way to play is with headphones, and with your eyes closed. You get into some sort of trance-like state, and start imagining the sounds you’re travelling towards. It is all very bizarre.