Hi!
Got to collect 10 birds, but had to collect 5 birds after finishing?
Quite innovative and thematic!
For the visual part, it might be better to bind the camera to the size of the map so that there is no empty black space behind the map.
As for the gameplay, sometimes the birds ran behind trees that I couldn't get behind :), but in principle it even amused me, because it added reality to the gameplay that you can't always climb where someone smaller can :D. Also perhaps I would like to see the start menu, with a description of the controls.
In any case, it's a fun game! Congratulations!