Does somebody know if this version of the game is shortened like the one on steam?
http://steamcommunity.com/id/criticalflaw/recommended/336780/

I was just checking this myself from from the 2 reviews of the third one, it looks like they are cut versions.

I just finished playing these games and did a bit of research.
The developer GOG shows is 1C Wireless instead of GAMOS and Pipe Studio. 1C Wireless is a division of 1C Company specializing on mobile games. What this means is that the versions GOG has are actually ports of original games for Windows Phone.

My assumption would be that these are the only versions which were translated into multiple languages.
Otherwise they are strictly inferior to original PC games.
Whereas content is concerned, the first and the second games in the series have been ported without cuts and the third lacks ten levels skipping from the base right to the tropical island, which is a shame.

I made a corresponding topic on the community wishlist:
https://www.gog.com/wishlist/games/brata_piloty_kollekcia_klassiki_dla_pc_pilot_brothers_classics_collection