I watched this cartoon movie in the early 2000s but I think it was made in the 70s or 80s. The movie was dubbed but had a German song at the beginning.
From what I can remember it is about a boy and a girl. They find a bug with a missing arm or leg that explains that the arm has been missing for generations because a woodchopper scared his great grandpa off the tree and his arm stayed on it.
The bug teaches the kids to fly and so the kids go to outer space or something like that and meet a bunch of entities like the Moon, the Sun etc.
They also have this jar of stars that tells the time. When the jar is empty the kids have to go home or something like that.
At the end, the kids find the missing arm on the tree but they had to fight the woodchopper first.
I've been trying to find this movie for over a year now. If you have any idea what it is please let me know.