Here is the full list of all 22 Pixel Puzzle Makeout League achievements.
Couldn't resist
Unlocked all special themes
Remade the world / Set off on your own
Remembered what part she is
Found true love
Saved Sudoku
Became whole with Piecea
Solved 200 pixel puzzles
Found the truth with Crossword
Completed the Puzzle Maze
Became partners with Chess
Made a costly mistake
Climbed a mountain with Piecea
Solved 100 pixel puzzles
Explored the digital realm
Survived an encounter with the Villain
Learned about Crossword's past
Let the timer run out
Went on a sneaking mission with Chess
Tried something new with Sudoku
Got to know a member of the Puzzle League
Escaped the Villain's clutches