R6dw6C: Since you didn't mention Gnther's Der Dritte/Her Third, I'm gonna assume that you haven't seen it. He was known as an experimental filmmaker and the film you brought up seems to qualify as such. It isn't available here. The one I reviewed is a more traditional social-realist piece.

Along with Westerns, DEFA also produced a number of Sci-Fi films. Kurt Maetzig's Der Schweigende Stern, Gottfried Kolditz's Im Staub der Sterne, and Hermann Zschoche's Eolomea are said to be the key works. Have you seen any of them?