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