Really cool experience, I love flying around! Especially loving the effects on colliding with trees :)
But I can't play this without a total freeze every several minutes... after which I have to kill the process. No idea what causes it, but the last time it froze right after pressing space and shift almost simultaneously (space quickly after releasing shift, i think).
Anyways, here is my output log if that helps, there is something about mono's security framework (?) https://pastebin.com/69aC3Umq