Nope. I just can’t do the half-pipey level at all. The game is clearly broken.
I did, however, manage to find an easter egg on the very first level when I was trying to improve my times. That gained me 5 gamerpoints and another achievement. Hurrah! I have a gamerscore of 120 now! Ph34r m3.
Whilst time-improving, I got thoroughly confused by the leaderboard system. I don’t understand why, despite having the fastest time (amongst my friend list) on several levels, I’m sometimes in 4th place or lower.