No Galaxy achievements on the GOG version sadly, the only thing that are sort of achievements are the in game tracking of % completion and speedrun % completion tracking to unlock extra artworks.

I would not count on achievements for Way Forward games on GOG.
I asked for River City Girls and they won't add them.

Steam has achievements for all the Shantae games.

I wonder why that is tbh. I mean I love achievements, but are also glad if a game doesnt have them since I often play offline and sometimes achievements wont get tracked which leads to me not wanting to play the game offline.
I mean it cannot be that hard to implement achievements on gog, can it? Or are the sales maybe too low?