Is there a possibility to add achievements to GOG version? The Steam version has it but i want to support both you developer and GOG as a platform plus i like the achieves system. Thanks in advance! :)

The game does have an in-game badge system with works fully regardless of the platform. I haven't integrated achievements through GOG though, and don't think it's feasible to do so (integrating them would require a separate GOG-specific build of the game for Windows, Linux, and macOS) given the relatively small demand for GOG achievements.

That being said, If I ever do add GOG achievements, all of your existing in-game badges will automatically unlock as achievements on GOG, the game wouldn't make you re-earn them.