Kingdom Hearts: Melody of Memory clearly isn't an RPG, but it does have some RPG elements. In an interview with VentureBeat, co-director Masanobu Suzui explained what elements of the RPG genre make their way into this rhythm game.
First of all, there is a progression system. You leveling your characters and powering them up. Your party members will have increased HP and attack power; they grow stronger as you level up. With more HP, you’re less likely to get a game over. If your attack power is higher, it’ll become easier to knock out your enemies. There’s also a system where you collect cards. They unlock support elements for your characters. You’ll also be prepping before each stage with items that you can use to bolster your party. With those items, you’ll be choosing five different types before going into the stage. You’ll be able to collect materials so that you can synthesize items, which can make battles more convenient. There are materials you can collect and use for synthesis, and they will also unlock new songs. We have different elements that allow for replayability, so players should be able to enjoy the game for a long time.
Of course, story is very important throughout the Kingdom Hearts series, and Melody of Memory isn’t an exception. We have a mode called World Tour. Your characters will use the gummi ship to travel around the different Disney and Kingdom Hearts worlds. There are certain missions you have to accomplish in each area, and when you clear that, you’ll unlock another section of the world. You’re following the storyline from the first Kingdom Hearts game, going through and revisiting different stories throughout your journey. You have different stages, and in between there are opportunities to watch past events as movie clips. We have Kairi narrating over that.