Crisis Core: Final Fantasy VII/Gameplay

One of the most important things to note for fans of the Final Fantasy series in general, and Final Fantasy VII specifically, is that Crisis Core is an action-RPG, and battles happen in real time (rather than in the turn-based system of the more traditional titles in the series).

Difficulty
This game allows players to choose between Normal and Hard difficulty levels. The only difference is that enemies inflict more damage, and the player's character inflicts less. Since the game also has a New Game+ option that allows much to transfer from a previous play-through, it is recommended to play on Normal difficulty first, and then try the higher difficulty later.

Stats
Level: Zack starts the game at level 6 and can achieve level 99 through the course of the game. In order to raise his level, he must earn the appropriate amount of experience. However, his level won't actually raise at that point unless 777 comes up on the DMW during the modulation phase. He will continue gaining experience towards the next level without having to get the numbers to come up, so it is possible that the wheel can keep his level low for a while, and then dump a few level gains on him in quick succession.

Digital Mind Wave (DMW)
The Digital Mind Wave is a set of three wheels (much like a slot machine) that spins in the upper left corner of the screen during combat, somewhat reminiscent of the system used in Unlimited SaGa. The wheel uses (automatically) 10 SP every time it spins, and causes Zack's level to increase, limit breaks, and level increases on his equipped materia.

The three wheels have 18 possible images, though normally only 6 human characters are available, and at the start of the game only Sephiroth and Angeal are on the wheels. Images are added to the wheels as the game progresses, and under special circumstances (Summon Mode, Chocobo Mode, and Genesis Mode, for example).

The limit guage above the DMW will range from slow blue waves to fast red waves, and is affected by how well/poorly Zack is doing in combat. The story can also modify the limit guage. In any case, as the guage moves towards faster and red, limit breaks become more likely.