Click the game.
Click 'Arcade'.
Click 'Watch'
Pause the recording when there's 0:32 left.
Press
.
Click Start Playing.
As soon as you start playing, press
.
Select 'Quit Game'.
Select 'Quit (Save)'.
Click 'Arcade'.
Click 'Continue'.
Shoot the few small enemies left.
This achievement will then pop as the screen goes up, and shows the huge green-clothed character.