Here is the full list of all 20 It Takes Two achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Scurvy! Ye look smashing, captain!
Don't feed the animals! Or do, they're adorable.
Shoot for the stars, literally.
Again? Keep track of your kids!
Isn't it pretty? That's going on the fridge.
Now look who's extinct!
All minigames found!
You did it! CO-LLA-BO-RATION!
You reached a higher state of mind. Or at least some peace and quiet.
Release that tension at the root level.
Took things a bit too far, didn't you?
Helltower? More like hello-from-up-here-tower!
Breathe some wind into your ocarina, my skyward princess!
Choo Choo!
Guess it was time to cash out.
Put on a show and die trying.
The truth was out there all along!
They had no way out.
Self-inflicted paparazzi.
It takes two to… torture.