Here is the full list of all 63 Pixplode achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Get three stars on fifty levels
Finish the game
Mr. Nobbs couldn't make it, unfortunately.
I shall call it... "Semifred"?
Awww, you shouldn't have...
And Obelisk... OK, now you try to write something funny there.
Thanks to emotes it has become much more popular than it's brother
Get three stars on forty levels
PLEASE, do not leave it unclosed
"Pointless"? I don't think so.
Complete level 30.
What is the purpose of this letter anyway? Either you read is as "z-" or as "ks-"
Get three stars on thirty levels
Finish level 16 in three moves.
Get three stars on twenty levels
Make a block fly very fast
Sooo, fifteen? Heh. Heh. Heh...
Short form of "AAAAAAAAAAA"
Get three stars on ten levels.
"You just rotated the 6, right?" - "No, it has a different background!"
What's supposed to be lucky there?
Complete all tutorial levels.
"(...) then shalt thou count to three, no more, no less. Three shall be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, neither count thou two, excepting that thou then proceed to three. Five is right out. Once the number three, being the third number, be reached (...)"
"Ein, zwei - polizei"
Remember - not a prime number.
Zero. Zilch. Zip. Nada. Nothing.