Bubble Witch 2 Saga has a special gameplay mode once you've passed Level 26, on the mobile apps only.
It is called Magic School.
In Magic School you'll be able to brew special potions to help you in the game.
Each potion requires a specific number and color of bubbles that can be collected as you play.
Then you wait the allotted time before you can use them.
(Scroll below to see what each potion can do)
This potion enables you to see a 3rd bubble, which can help plan your shots.
To get this potion you need to collect 80 red bubbles, and can use it after a brewing time of 30 minutes.
This potion makes a Sparkle Shower fall across the game board.
To get it you need to collect 160 yellow bubbles and it can be used after brewing for 60 minutes.
This potion extends the aiming line so you can make more accurate shots.
To earn this potion, you'll need to collect 200 blue bubbles. Then you have to wait 1 hour 15 minutes brewing time until you can use it.
This one rains down stars that burst across the board.
For this potion you need to collect 40 star bubbles.
It takes 2 hours to brew.