On my third try I got 110 or so biscuits; the controls feel bit tricky because there is so much inertia - but I guess one gets used to that on repeated play troughs. I recalled the skydiving in Pilotwings 64 (old Nintendo 64 game) because that one had pretty good skydiving controls, but I don't know if you know the game.
You should mention on the game page that the mouse controls the camera - I think I did not realize that until second play trough. Controlling the camera with mouse and movement and speed with keyboard is kind of an hassle - maybe you could find better solution to that?