I can confirm this happens with this achievement save file as well, found here: https://steamcommunity.com/sharedfiles/filedetails/?id=2344777605&searchtext=rocket+save

After pressing "Finish" on the victory screen, I didn't get achievements for quick victory.

Repro:
Delete your achievements in ...

I am not sure how to modify my earned achievements to try and reproduce it. If I understand correctly, earned achievements are not tied to a save file. I cannot find where they are saved in my user data.

Not sure how useful it will be, but here's the save where this happened anyway.

After finishing the game for the first time by launching a rocket and clicking "Finish" on the victory screen, I wasn't awarded any achievements (in my case, this applied to "Smoke me a kipper, I'll be back for breakfast", "So long and thanks for all the fish" and "Raining bullets". It likely ...