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