A great game... with some confusing aspects.
First off, let me say this is a great game, full-on five stars and highly recommended. You can try the free version first to see if this is the sort of game you enjoy. You connect same-style tiles to get the background to a solid color and then to drop an icon off the field, all under a time limit.
The music, sound effects, and graphics are all excellent, making this an enjoyable and even addictive game.
Having said that, even after completing all the levels successfully I cannot figure out the rules that govern when a tile changes color. All I do is look for tiles that can be connected, longer strings being better, and all-blue strings being not as good. And the background story (something about having found several talismans in Asia) makes no sense to me, and seems irrelevant to the game itself. However, this does not detract in the least from the game. Well worth the three bucks.