Currency

Coins
Used for buying both new guardian eggs and upgrading coin capacity via buying additional Treasuries from the shop. See also Coins

Best Levels to farm Coins:


 * Mountains > Spruce Cones > Merge Amber
 * Levels with Mud Springs

Stones
Used for upgrading stone capacity via buying additional stone mines from the shop.

Best Levels to farm Stone:


 * 50,51

Crystal
This is the premuim currency, it can be bought in game for real world money, or and crystal gems. Used in many ways all throughout the game.

Acquired in-game from:


 * Crystal stars (during star rain it can spawn one at the end)
 * If one appear during a level, do not collect it, you will be able to get it for "free" at the completion of the level and take it back to your harbour for further merging.
 * It is reccomended to merge these to the highest level before collection.