Here is the full list of all 42 Only You achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
First Restart
Game Over
First Death
End Game
12 Lvl completed
Music 12
Last Step
11 Lvl completed
Music 11
10 Lvl completed
Music 10
9 Lvl completed
Music 9
8 Lvl completed
Music 8
7 Lvl completed
Bandit 3 Dead
Music 7
6 Lvl completed
Music 6
Middle Game
5 Lvl completed
Music 5
4 Lvl completed
Music 4
1/3 of the game
3 Lvl completed
Music 3
2 Lvl completed
Music 2
1 Lvl completed
Bandit 2 Dead
Bandit 1 Dead
Jump
Go Left
Go Right
Mute
Pause 2
Pause
Fall
Start Game
Music 1