Complete Level 20 and you will unlock "Sheep Gifts".
Sheep Gifts are bonus Mana Gifts placed on the game board at the start of play on puzzle levels.
Complete multiple levels in a row and you will start subsequent levels with Mana Gifts placed on the board.
Complete more levels in a row to improve the Mana Gifts you start with.
There are 4 levels to this bonus, and the level will reset to 0 if you fail to complete a level.
*If Mana Gifts are placed on the board as a result of Sheep Gifts, your own Mana Gifts will not be used up.