Bonus multipliers will often appear after you have pushed all the gem bubbles together, although they can appear in other instances. The multipliers range from x2 - x5. The multiplier will calculate your bonus at the end of the level. If you collect a bonus multiplier an icon of its value will show to the right of your current bonus amount. If you collect one multiplier, then collect another, the last one collected will replace the previous one, regardless of its value.
Bonus points found in a bubble, if caught, will simply add their value into your current bonus amount. Try not to miss these!
Collect the Bonus letters to spell the word EXTRA. As you gather letters, they will be displayed in the status bar at the bottom of the screen. If you already have that letter, then nothing will happen. Once you have collected all the letters to spell the word EXTRA, you will receive 10,000 points.
Catching the bubble with a light colored Blinky inside will make your Blinky invisible for a short while. When you are invisible, you cannot pass through bubbles, however, you cannot be harmed by enemies. Be careful though, Blinky will start to blink when the effect starts to wear off.
The bubble with a cluster of balls inside will not directly affect Blinky. When you catch this bubble, about 10 blue, rubber bubbles will appear. When you push them, they hit a wall and bounce back. If Blinky bounces a blue, rubber bubble, the blue, rubber bubble will bounce back. If Blinky bounces a purple rubber bubble, the purple rubber bubble double bounces. Say that five times fast!
Capturing the bubble with an enclosed fish inside will capture all the enemies in green bubbles. However, green bubbles are not as strong as regular bubbles, so the enemies will eventually free themselves.