To complete the level in adventure mode, immediately go for a green peg, and on the next shot get the ball to go into the far left or right side snake so that it will fall from top to bottom down the side of the screen hitting as many orange pegs out of the snake as possible. Next, clear out orange pegs in all but the opposite side, but don't hit the other green peg yet. Then for the second snake, get the second green peg, and your "Zen" shot should get most of the rest in the snake (using the same top to bottom type shot as the first).