Final Fantasy XIII's gameplay is proving, as expected, to be quite a bit more complex than the first demo suggested.
The demo version of the PlayStation 3 and Xbox 360 game, presented at Tokyo Game Show on Sony's console, is centered around introducing players to two of the game's new combat systems: Optima and Driving.
The "Optima" system is a means by which character input is automatically simplified into a series of set patterns that combine attacking, assisting, and healing. In the original demo of the game, you had to select up to four different actions for the game's main character when it was their turn to attack, chaining together different combinatins of moves depending on what your situation was. When using the Optima system, you simply select "Attack" from the game's main menu, and the game will execute a series of commands based on the type of Optima you're currently using.