Bubble Bobble/Levels 21-30

Level 21
Jump up the center column, and capture the stoners. This will encourage the Bubble Busters to jump up, allowing you to capture them without issue.

Level 22
Bounce along the lightning bubbles that float along the side, while facing the outside wall. When they are aligned with the enemies, release the jump button to pop the balloons.

Level 24
There are seven hullaballoons in a row, near the top.