Here is the full list of all 32 Knuckle Sandwich achievements.
Gotta find 'em all.
I told you not to eat that!
You can do it.
No wrong answers.
Beat the Exterminator minigame.
Beat the Space Cleaner minigame.
Leave no stone unturned.
Beat the Dancer minigame.
Get an A Rank in the Diner minigame.
Get an A Rank in the Cooking minigame.
Make him mad.
YEEEEEEEOOUCH!
Earn their respect.
Hate the planet.
Time for a visit.
Run into some familiar faces.
Thea.
Echo.
Dolus.
Brightside.
What are you doing?
Someone had to do it.
A chance encounter.
Find Challenge Mode.
Beat the game in Challenge Mode.
Get an S Rank in Fortunate UFO Collection.
Get an S Rank in Can I Survive this Endless Jogging Fantasy?!
Get an S Rank in The Very Hungry Yeti.
3AM Challenge.
Amazing.
Find every decoration for your home.
Beat the game.