Finding the windbag is indeed the easteregg, but it should be doable without the airplane :D

>Elevator: When I call the elevator and my clonk is standing directly below it, the elevator does not drive directly down to the feet of my clonk, but stops a few pixel higher. Therefore grabbing the elevator and pressing [up] results in the elevator driving upwards without the clonk on it.

Agreed, currently the elevator has the new special solid mask which allows you to fall through when pressing X, this cause more problems like only pushing stuff up when they are above the solid mask and not in the solidmask. Also tutorial 5 the outro is broken because of this. I'll look into adjusting the elevator case movement a bit.

>Selection circle for objects you can grab: Should in my opinion only appear if you hold [space] a bit longer (so you actually want to select between different objects).
>                                                              Looks weird and makes no sense at all to show the selection circle for under a second when just  pressing space shortly, especially not when there is no other grabable object around.

I have no strong opinion on this, so Zapper will probably reply here.