In the last cavern in Hidden, the one with the thing, there seems to be more vertical air resistance than horizontal. It's hard to describe.. If you set the star on a diagonal path, it slowly curves towards a horizontal line. It's clearest to see on a diagonal path close to the horizontal, because then the star's trail ends up as a neat curve with a straight horizontal section on the end. Odd really.

I'm going to investigate hidden's glitches, see if I can spot anything other than this friction bug and the phantom orb particle glitch.

P.S. Sorry if my spoiler is ugly, I can't find a decent guide to spoilers on the forum (though I've seen Paula's FAQ on naming them), and I'm sure it was possible to make spoilers fit into the line before, rather than doing the new line thing. If it isn't, maybe I'm delusional