Angry Birds POP! Level 18 is the 3rd level in Waterfall and the 5th Pop the Top level in Angry Birds POP!. To pass this level, you must clear the six bubbles at the top row and score at least points in bubbles or fewer. When you complete the level, remaining bubbles and obstacles will reward you additional points.
Clear the one side of the bubbles and use your powerup to hit the highest and drop more bubbles for points.
For a list of level versions, see Angry Birds POP! Level 18/Versions.