KOF: Maximum Impact Regulation "A" is a rebalanced version of The King of Fighters 2006 originally meant for competitive arcade play. Four new characters make an appearance: Ash Crimson, Blue Mary, Mizoguchi, and original character Xiaolon.
Most of the single-player modes from the original game have been stripped out, and the focus is now on versus play. Gone are the story and mission modes, as well as the unlockable extra costumes. All the available costumes and characters are available from the beginning.