PSN Stores says: "...If I could change one thing about this it might be the amount of grinding one has to do to get cards. After you clear all 5 stages on a phase you unlock a card that is from Sony's "The Eye Of Judgment". These cards are extremely powerful and also extremely expensive. I had to grind for a few hours just to get enough for one of them. But I can't really fault the game for that, it keeps bringing me back. This game has got its hooks in me and I don't see them coming out anytime soon."