Most people must have gotten it from CD-Action, which was THE monthly gaming magazine at the time. Each copy came with a DVD containing a few demos of upcoming games and 1-2 full games, most of them titles a few years old. Colobot made an appearance sometime in the mid-2000s.
Yep, that's how I played it. Loved it as a kid. Also I'm reasonably certain it was bundled with "Komputer Świat" not CD-Action since it was more of an "educational" game, CD-Action did more "mature" releases. But I might be wrong.
I've talked to several of my friends and people in general and to my surprise this game had been somewhat popular in Poland.
Have you ever heard of this game? It utilised a C++ like language that you could write your scripts in.