1. Only from the above.
2. It's possible to get into the other side.
3. Not unfortunately :(
4. ^ See 2. ^
I'd suggest you to try it again,
no one has made it yet.
*spoilers*
I take back my comment about the controls. After playing more and getting the hang of things, I think it's at a good level of difficulty. Since there's no enemies, there should be a challenge somewhere, and completing some of the harder jumps is definitely rewarding!
Ah, the missing bird bug resurfaces. I've no idea atm why and how it happens. :D What I've gathered is that the bird should return after the player goes a few screens away and then comes back, but it's still a guessing game...
Also, nice to hear that the controls "clicked". I'm still pondering if I should tweak them a bit, but this reassures that platforming physics are at least 95% complete.