Managed to do the half-pipe level! Hurrah! It seems the trick is to jump repeatedly across the “bottom” of the pipe, which makes you build up speed to make it up the other side. I still couldn’t manage the other two Advanced levels though – the mountain one, and “Schadenfreud” or whatever it’s called. Pah.
Went and did a load of Intermediate again to get Par times. I only have two left to do – the spelunking one being one.
After that, I played against Beck online, and beat her twice. The best bit, though, was getting 75 points in the first match, gaining me two achievements. 150 gamerpoints now. ACE.