Humans coexist with intelligent androids called "Reploids". Following the third defeat of the powerful, "Maverick" Reploid Sigma, a second Maverick Hunting group has arisen. The army, called the "Repliforce", is a strict military regime led by the giant Reploid named General and his second-in-command, Colonel. Battle armies of Maverick Reploid Robots while mastering all-new strategic moves like the Air Hover and Zero's Saber Tactic system. Discover a myriad of power-ups, secret rooms, extra weapons and invincible vehicles to take on 8 all new X-Hunter Bosses. Experience two different story lines and characters with their own sidekicks. If you play as X, your experience will be very similar to the other MEGA MAN X games, while if you choose Zero, the story is pretty much the same, but you have to change your approach in battles and traversing the terrain. Mega Man X4 - now you can be a hero, or a Zero!