Mega Man Zero 4 is a video game developed by Inti Creates and Natsume and published in 2005 by Capcom for the Game Boy Advance (GBA) handheld. It is the fourth and final installment of the Mega Man Zero subseries of the Mega Man franchise and is set several months after the events of Mega Man Zero 3. The European version featured a completely different logo, which was also used on Mega Man X7, Mega Man X8, Mega Man X: Command Mission, Mega Man Zero 2, Mega Man Zero 3, Mega Man Network Transmission, Mega Man Battle Chip Challenge, Mega Man Battle Network 3, Mega Man Battle Network 4, and Mega Man Battle Network 5. The game deals with Dr. Weil's reign over Neo Arcadia in which humans, who have been reduced to second-rate citizens, begin to escape in large numbers to the last-known livable location on the planet, Area Zero, beginning a conflict between the two groups. The effects of this war eventually drive Zero and the Resistance to protect Area Zero and its inhabitants from Dr. Weil.
Since its original release, it has been brought to the Nintendo DS family of systems as part of the Mega Man Zero Collection in 2010 and the Wii U's Virtual Console in 2016. In February 2020, it was released on PC (Steam), Nintendo Switch, PlayStation 4, and Xbox One as part of the Mega Man Zero/ZX Legacy Collection.
The fourth installment of the Mega Man Zero series introduces gameplay changes, but does not deviate from the platforming of its predecessors. Players guide Zero through eight main selectable stages, which are usually separated into two parts by a mini-boss battle. At the end of each level, the player faces one of the game's reploid antagonists.
Mega Man Zero 4 includes a new Easy Mode, not found in its prequels, in response to criticisms that the Mega Man Zero series had become too challenging. In Easy Mode, Zero receives a large life boost and can use the Cyber Elf without restrictions. However, Easy Mode prevents the changing of the weather, and consequentially the acquiring of EX Skills.
Zero is still equipped with the Buster Shot and Z-Saber at default. However, in place of the Shield Boomerang and the rod-type weapon from the previous games (i.e.: Triple Rod, Chain Rod and Recoil Rod) is the new Z-Knuckle. This device allows Zero to perform several actions, including hanging from pipes, destroying obstacles, stealing an enemy's weapon (if Zero destroys it using the Z-Knuckle) and acquiring special weapons in certain parts of a stage.
Another new element is the weather system, which allows players to choose between two weather conditions for each of the eight main stages. The difficulty of the stage varies depending on the chosen weather condition, with the stage being harder if the weather icon has an orange border around it. Sometimes, there are secret passages in some stages which the player can only reach by setting the weather to "hard". The trade-off for an easier level is that Zero cannot learn an EX Skill from a boss.
Cyber Elves, a core element of previous Mega Man Zero installments, are small helpers who can assist Zero in combat. Shortly after the introductory levels, a Cyber Elf will arrive for Zero to equip. This elf has most of the powers of Cyber Elves from previous games, which are unlocked as the player raises its level by feeding it E-Crystals. Zero may select one power from each of three categories: Nurse, Animal, and Hacker. The player's ranking at the end of a level is no longer given a penalty for using the Cyber Elves as long as they are kept under the maximum power limit. In addition to this, Zero can now equip body chips to enhance his abilities, including double-jumping and self-recovery, similar to early Mega Man X titles.
Zero cannot rely on finding secret disks to give him enhancements as in Mega Man Zero 3. Instead, players must collect parts dropped randomly from defeated enemies. Recipes for combining these parts can be obtained from NPCs the player rescues or a Cyber Elf after its stages of evolution. However, the majority of the recipes are found through experimentation with combinations of parts.
Another distinguishing feature of this installment is that Neige and Ciel have different faces depending on their emotion. For instance, after Zero "dies", Ciel is sitting near a tree and tells a promise that saddens her and brightens her. Neige also has an angry face, one that Ciel lacks.
