Along with what Marta said above, I would add three things
There is a second game mode called Survival which unlocks after you earn the first Talisman. You can play/replay it at any time after that.
The game is not a killer, but it isn't a walk in the park either once you reach the last 1/3 of the game.
The cut scenes are really quite beautiful, and at the end of each section of the game, they provide the back drop for a mini game.
I really like this chaining Match 3 game.