Finally passed the AppSchtore Bergwerk:

On the way, it had to change its name and the objects in the game had to undergo a shape transformation from rounded square to egg.

Use your imagination to transform the E->A, g->p and eggs into ???s. Being a subscriber to the german BitsUndSo Podcast ( might also help to understand what the game originally was about, and what a AppSchtoreZwerg is...