Complex sentence: This system was abandoned for the "Persona 2" games: the party has free movement across the battlefield, and is assigned a set of moves which can be changed in the menu during and in between battles.
Split into simpler sentences: This system was abandoned for the "Persona 2" games, with characters instead being able to perform an action on any area of the battlefield. In the "Persona 2" games, the party is assigned a set of moves, which can be changed in the menu during and in between battles.