Check your Core Keeper achievements
Pick your character file and this page reports on all 59 achievements. It only ticks what it can prove. Add Steam's record as well and it can answer all 59 exactly.
Nothing is uploaded. Your files are read entirely inside your browser, and never sent to the dashboard or anywhere else.
%USERPROFILE%\AppData\LocalLow\Pugstorm\Core Keeper\Steam, open the folder with your number, then
saves. Files are named by slot: 0.json, 1.json and so on.
C:\Program Files (x86)\Steam\appcache\stats, in the file ending _1621690.bin that starts
UserGameStats. It covers your whole Steam account, not one character or world, and it's only as new as
Steam's last sync.
Maxed skills
Proven from your file. Level 100 earns each one.
Legendary items
Proven from your file, using the game's own check. One you haven't found stays hidden until you tap it.
Cook book and outfit
Proven from your file, using the game's own rules. An outfit only shows while you're still dressed that way.
Bosses
From this server, the same rows as the dashboard. The game gives these to everyone online when a boss falls, so this says what the server has beaten, not whether you were there.
Hints from your file
Your file shows signs of these but can't prove them, so they're never ticked.
Not in your file
The game decides these on your PC or on the server, and doesn't write them to this file. Steam's record answers them.