As the player plays through scenes, a player fills up a mastery star meter based on the number of points earned for that scene. For most scenes, there are 5 mastery stars available, while some scenes such as the featured scenes, only have 3 mastery stars. Filling up a mastery star typically provides a reward such as Paper Houses, or Paper Lanterns, or even Gems (for Imagination Scenes). The more mastery stars achieved on scene, the more difficult the objectives are.
See Mastery Stars for more information.
As the player plays through scenes and crafts items, the player will accrue experience points. Reach a certain amount of experience points, and the player will increase in level. Currently, increasing a level provides a Gem, 1 or 2 of a certain ink, and a complete refill of the player's fuel. Note, however, If the player is playing on both a mobile device and on the PC via Facebook, fuel is only refilled for the platform currently being played when the level up occurs (Example. Leveling up on the iPhone will refill fuel on the iPhone version of the game but not refill the fuel on the Facebook version of the game).
See Levels for more information regarding the experience required for each level and the rewards granted.