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.
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.
Again? Keep track of your kids!
Took things a bit too far, didn't you?
Breathe some wind into your ocarina, my skyward princess!
Choo Choo!
Guess it was time to cash out.
Shoot for the stars, literally.
Self-inflicted paparazzi.
It takes two to… torture.
All minigames found!
They had no way out.
The truth was out there all along!
Put on a show and die trying.
Now look who's extinct!
Isn't it pretty? That's going on the fridge.
Helltower? More like hello-from-up-here-tower!
Don't feed the animals! Or do, they're adorable.
Scurvy! Ye look smashing, captain!