What are pre-level boosters?

At the start of every level you will have the option to choose boosters to help you complete the level.

The booster options are:

• Bombs - a bomb is placed randomly at the start of the level.
• +3 Moves - increase the total number of moves available to complete the level by three.
• Rockets - a rocket is placed randomly at the start of the level. 

These boosters can be purchased at the start of a level with silver coins. Just tap the boosters that you want to use on the pre-level screen so that a green checkmark appears next to it, and the booster will then be available for that level!