I thought at first there were no clues and it would be a waste of time. Then i rotated the level and could see the ball landing in the wrong places and its trajectory which led to my win.
I got there, but it was really just by systematic trials of combinations. I wondered if the red bricks in the tower were a hint but couldn't spot any meaning in them?
Nice and easy puzzle. Spoiler: The hint is the lower green. Check the corner of the rotatable parts. Thanks for sharing