Hello! You can describe the issue here :)
Although, I'm not sure if that's possible to fix issues in Starless now because that was the old version of Game Maker
This concerns the achievements of the GOG version of the game. They aren't working right now, but they can be enabled using the GameMaker extension created by YellowAfterlife, which you can find at this link:
https://github.com/GameMakerDiscord/GOG.gml
It would be great if you could update the game on last time, and I know a lot of other people who would be really happy about it.