Here is the full list of all 18 One Pixel TWB achievements.
Time to take a nap
I think you beat all the bosses
You won boss number 1
We can start?
You won boss number 2
You won boss number 3
You won boss number 4
You won boss number 5
You won boss number 6
You won boss number 7
You won boss number 8
You won boss number 9
You won boss number 10
Believe me when I say that some can't get through
What's going on here?
This guy is not happy with you
We have here a born explorer
You are looking at the most amazing cat of all.