I finally figured out how to beat this with only 22 balls. First tip is ignore all the how-to videos based on 30 balls because that technique won't work with 22.

1. Knock out the first group of bubbles by hitting the single row of 3 bubbles at the top. Once that group is gone don't worry about the two orange bubbles or the black bubbles. (I always go with the blue ball and hope to uncover another blue ball. If you get a mixed bag of colors you'll end up wasting too many balls to clear this section that the rest of the level will be impossible. In that case I usually just restart and lose a life).

2. Bank 3 balls off the top left side of the wall to hit a vortex semi-hidden off screen in that corner. Then fire a blue ball into the same place and it should hit a row of blue bubbles that will dislodge every bubble on screen. It has to be blue.

3. Now bank 3 balls into the vortex in the upper half of the new screen. Again fire a blue ball into the exposed row of blank balls right where the other blue ball is and it should dislodge the lower group of balls.

4. Now fire 3 more balls into the last remaining vortex in the upper right area. Use a yellow ball to knock out the next large group of balls.

5. Now you should be left with around 15 balls at the top and it's really just a matter of killing them off in a straight forward manner. If you have the special ball that'll help to fire into the blank balls.

It all relies on you being lucky and getting the right colors at the beginning. If you have to waste too many balls to clear the lower half of the level you won't have enough left over.