There are 14 achievements I can not unlock (1 can only be unlocked on certain dates). They are all the Legendary ones without the %, as of writing this.

Big Bag of Tricks
Bushidissimo
Slapping the Mosquitos
Three Little Pigs
Trick Shooter
Using the Tools

8 hidden achievements


There is one hidden achievement to get past 1,000 turns. I couldn't get it to pop.

Three Little Pigs It is necessary to bombard the besieged planets. Learn technology, military technology tree. Make a ship like "B-52" with bombs.
Trick Shooter Use DLC Disharmony. There are three targeting options, we choose before the battle, "spread fire", "nosebreaker", "guillotine". use all three methods.
https://steamcommunity.com/sharedfiles/filedetails/?id=2269650144
Using the Tools There are 6 fleet formations. Use in 6 battles.

Were you able to unlock those achievements? I feel like Trick Shooter and Using the Tools shouldn't be legendary achievements without any %.

achievements Trick Shooter and Using the Tools Unlock in Steam verison ES

Sadly what works on steam won't necessarily work on gog.