Basic formula, match quantities of the same color up with each other to break them. Set up combos by placing matching colors away from each other and causing them to crash after the colors in between them are eliminated.
For all intents and purposes, the game is quite challenging. For that I give it a lot of credit. You have to have a quick eye and fast fingers to top the best computer players in the game. You are better matched when playing against a human opponent. I find this to be a failing point for the game though. There should be more opportunity for a learning curve and kids will have a hard time mastering the game because it goes from instruction to hard gameplay with the snap of your fingers.
It is good, but there is better for you out there.