I would like to personally strangle the dev's with a coat hanger. Good game, though.
The AI cheats, plain and simple. Back in the 8bit/16bit days of gaming, the processing power and interface of games limited the intelligence of the AI. So in order for those games to present any sort of challenge, they either threw hordes of enemies at you or made the enemies so overpowered, you stood little chance (Smash TV). Or they would blatantly cheat to "level the playing field", so to speak (Excitebike).
Well, with all the horsepower of modern gaming and the fact that AI is better than ever in smaller packages, the devs of this game decided to harken back to the days of yore for challenge.
Make no mistake, the AI knows what is going to fall from the top. It will remove a set of 3 with a known set of 4 showing, which is dumb for a human, only in this case it works out better because the ensuing dropped pieces manufacture a Godly combo of mana and extra turns/wildcards.
Its a dastardly precognition you, the player, do not have. The most revealing evidence that this game's AI was designed to cheat though is the AI's complete lack of advantageous spellcasting. Let me explain.
I already mentioned the AI knows what pieces will drop, which is a HUGE advantage. So with that, it goes without saying that the AI always has A LOT of mana. Most of the time, they have full bars. Only it doesnt use it as often as it could (as in, every f***ing turn, if it wanted to). With the amount of mana the AI has and some of the overpowered spells in game that only it possesses, the AI could wipe you out every game before you even got a turn (in most cases).
Then why doesnt it, you ask?
Ahhhhh, good question. Well, it stands to reason that the devs designed this game to, well you know, make money in sales. What fun would a game be that you couldnt possibly beat, right? So the AI will horde a lot of mana with its magic precognition, but rarely use it so as to give you a chance at winning.
Its that simple. What it really boils down to is that , you never truly "defeat" the AI, so much as it just lets you win from time to time. It cheapens the whole game when "winning" isnt really winning at all.