I downloaded Star Vikings today for Windows, and while the installer has an option for German, the game itself doesn't. The only language options are English, French, Italian, and Russian. Neither Spanish nor German can be chosen in the settings. According to the changelog, any version that has Russian and French should also have the other languages.

I figured out the source of the problem. I'm playing this on a Windows tablet, and a normal touch apparently sends two clicks instead of one, causing it to skip options in the menu. Possible fixes are:

1) using a bluetooth mouse, or

2) doing a quick double tap which will send 3 clicks; this way one can "alternate" between one set of 4 languages (English, French, Italian,
Russian) and the other (German, Portuguese, Spanish, HUE-BR), and then use normal clicks to get the desired language in the relevant set.