Getting airtime in the beginning was confusing, but pretty awesome once you could chain a few rings :) Continuously holding space seemed to help :P
The time-stop mechanics clashed a bit with the hang-time mechanic though, especially when you wanted to fall to hit a ring etc.
Reached the portal with around 40M in score, but hung around til almost 80M trying to see if I could go higher/enter the portal to no avail :P