1. Duzen oder siezen
There is a mix of the informal "du" and formal "sie" in the translations.
There should be a decision made for either or, possibly even by Scirra as this changes tone and perception of the software.
(Windows and Google uses "sie" while Twitter uses "du" for example)
"Du" allows a more direct translation and sounds more approachable. Even alot of the Professors at my Uni are using the "du" now and I think overall usage of "sie" is going down.
But some, especially older people might find it disrespectful.
2.Consistency in the translation of gravity
Sometimes "Gravitation", "Gravitationskonstante" or "Schwerkraft" is used.
I would advocate for "Gravitation".
3. Consitency in the translation of rotation
Sometimes "Drehung" or "Rotation" is used.
I would advocate for "Rotation".
4. Translation of Eases as "Lockerungen"
I don't think this is a good translation and I would prefer to use the english terms: Eases, Ease-In and Ease-Out, as they are used by German animatiors as well afaik.
5. Translation of Drag-and-Drop as "Ziehen und losslassen"
I don't think this is a good translation and I would prefer to use the english terms: Drag-and-Drop, as they are commonly used in German as well.
6.Translation of Next, particualrly in cases of a buttons.
Sometimes "Nächste" or "Nächstes" is used, should be unified imo.