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.
11 Lvl completed
5 Lvl completed
1 Lvl completed
Go Left
Go Right
First Restart
2 Lvl completed
Music 2
3 Lvl completed
Music 3
4 Lvl completed
Music 4
1/3 of the game
Music 5
6 Lvl completed
Music 6
Middle Game
7 Lvl completed
Music 7
Bandit 2 Dead
8 Lvl completed
Bandit 1 Dead
Music 8
9 Lvl completed
Music 9
10 Lvl completed
Music 10
Game Over
First Death
Bandit 3 Dead
Music 11
End Game
12 Lvl completed
Jump
Music 12
Last Step
Pause 2
Pause
Music 1
Fall
Start Game
Mute