The Mega Man Zero series is the fifth series in Capcom's Mega Man video game franchise, created by Keiji Inafune. Consisting of four games developed for the Game Boy Advance by Inti Creates, the series began with the release of Mega Man Zero in 2002. Like the Mega Man X and classic Mega Man series, the Mega Man Zero series is a 2D platform game with run and gun elements that places a heavy emphasis on memorizing boss patterns and selecting the correct weapons to use against enemies. Unlike previous series, the stages of the Zero series are interconnected by an overworld map. The player is assigned missions in Mega Man Zero, but Mega Man Zero 2 and later entries returned to the standard format that allows the player to select a mission from a stage select screen. One noticeable change from previous Mega Man series is the ability of the main character Zero to level up his weapons and gain new skills by defeating enemies. A new Cyber Elf System allows Zero to equip small helper beings known as "Cyber Elves" to assist him in combat. This system can cause permanent changes such as increasing Zero's life bar or even covering dangerous spikes, or grant temporary enhancements, such as the ability to deflect bullets for a short time. Zero can equip three Cyber Elves, but doing so causes a drop in his rank level. Later entries in the Zero series had more lenient prerequisites for the usage and consumption of Cyber Elves. Another new addition to the franchise is the presence of elemental weapons; Zero gains three element chips that can be attached to any of his four weapons--the Z-Buster, the Z-Saber, the Triple Rod, and the Shield Boomerang. Doing so adds elemental effects to his attacks. Games Mega Man Zero ...Game Boy Advance Mega Man Zero 2 ...Game Boy Advance Mega Man Zero 3 ...Game Boy Advance Mega Man Zero 4 ...Game Boy Advance