The game focuses on fights, which can support up to four characters. In versus mode, players fight in levels which have random item drops at times. Players may also use orbs to unleash powers and may also customize their characters, use different weapons, and can disarm opponents mid-battle. The story mode takes place months after the events in Onimusha 2, and eleven years before the events in Onimusha 3.
The action is similar to Nintendo's Super Smash Bros. series - two to four characters fight on a 2D plane. But, the game does have a bit of depth to the fighting, such as "Critical Attack/Counterattack," combos, melee items, and "Charged Attacks."
Critical attack/critical counterattack is a technique that's use in the core Onimusha games. Critical attack is when a enemy about to strike the player, the player has to strike back at the last possible moment - thus triggering the critical attack feature - a very powerful attack will occur and will perform heavy damage on the opponent. And critical counterattack is similar to critical attack but done differently, when the enemy is about to attack the player must block the attack at the last possible moment and fellow it up with an attack of his or her own.
The game also has charged attacks. Three different levels of power and three different versions of the charged attack is available to the player. The charged attack is done by holding the square button, the longer the button is hold, the more powerful the attack will be -the maximum of the charged is three. After the charged is good and ready for the player, he or she can perform one of three attacks - one being a projectile attack that's done by pressing left or right on the D-pad, the second if a multi-hit attack that's done by keeping the D-pad in neutral position and then releasing the square button, and the third is a powerful stab that's done by holding the R1 button after releasing the square button.
There is also a deep customizable weapon system in which you equip different weapons to different warriors.
- Three Eyes/Musaid/Gramusaid
- Zombie Warrior/Jaid
- Zero (Mega Man)