PROTIP: Angling shots right is /essential/ to getting the Hard badge. Remember, the ball can bounce between tight spaces and destroy wooden blocks in one shot instead of two if you angle it right.
I did it on total accident, but I had CellCraft up in the background (sitting at the beginning of the tutorial after you hit Play Game) and the song there makes this game seven times more awesome, I suggest checking it out. And to the developer, you should look into the music CellCraft used if you decide to make another game. The combination makes this game absolutely divine. I'd rate higher than 5 if possible.
Painfully easy if you know how to look at cross-eyed stereograms. XD Cross your eyes, look at it, and all the differences blink in the foreground. Simple as that. On another note, though, it is a beautiful game. I appreciate the work and effort put into it. The music is a nice touch. Better than all the random tech songs thrown into flash games these days.
 "DJManiax"){kind=icon}
 "Save Toshi"){kind=icon}
 "You Find Yourself In A Room"){kind=icon}
 "William and Sly"){kind=icon}
 "Museum of Thieves"){kind=icon}