Comment by giantrobot

AFAIK this was the case. I played a lot of Stars! (almost exclusively the shareware) and it had all the races and tech trees. It showed higher level tech trees but those were only available in the registered game. Map sizes were also limited in the shareware. Later versions might have required additional resources for the retail upgrade but I believe the version I had (2.5?) could become the full registered copy with just a key.