I've been playing KH- CoM, and that card system is like... really hard to get used to.
You use a card for every attack, even the normal weapon attacks. So what happens when you run out of cards? You go to the recharge card! You can recharge three times at once, and at the moment, that gives me 23 attacks total before I have to recharge again.
Then, if you want to use magic, you'd better hope a magic card pops out of nowhere, WHICH HAPPENS ALOT! XD
They just randomly pop out in a battle more often than you think.
When you want to use Goofy, you must pull your Goofy card. The same for Donald and any other chars you have. Which is really wierd XD
The BIGGEST problem, is scrolling through cards when you need to do a particular move quickly. Because each attack card makes a seperate card on the list, 23 attacks, means 23 cards you have to scroll through to use Cure. XD(why don't they just have a single attack card with a number on it?)
To move from one part of town to the next, you have to use map cards! You can't open a simple door without using the right combonations of map cards. And you get 90% of your map cards from battles, meaning that you MUST battle lots of random useless battles to progress through the game.
Once you get used to the card battle system, it feels just like playing KH, so the game definetly gets better after the first half hour of battling XD