First off, it's at turn based RPG with a 4 man team.

Each character has AP, which represents the amount of actions they can take. You have 4 options in battle, the rush attack which hits multiple times, the harder attack, a magic attack against all enemies, and the slot, which can have multiple skills in it. You charge it to determine which skill to use, the longer you charge the more AP it uses.

If you, for example, string 5 rush attacks in a row you'll use a special skill. Each character can use most of the same button combos for attacks, though the attack varies from person to person, and each character has a few unique patterns to them.

You can also string characters attacks together to obtain higher hit combos, bonus's to a characters stat for that round, or other such things.