Mega Man X4

Complete Sky Lagoon

Defeat Web Spider at the Jungle

Defeat Cyber Peacock at the Cyber Space

Defeat Storm Owl at the Air Force

Defeat Magma Dragon at the Volcano

Defeat Jet Stingray at the Marine Base

Defeat Split Mushroom at the Bio Laboratory

Defeat Slash Beast at the Military Train

Defeat Frost Walrus at the Snow Base

Defeat Colonel at Memorial Hall with X

Confront Colonel at Memorial Hall with Zero

Defeat Colonel at the Space Port

Complete Final Weapon Stage 1

Defeat ??? at the Final Weapon with X

Defeat ??? at the Final Weapon with Zero

Beat the game with X

Beat the game with Zero

Equip X with the boots upgrade

Equip X with the head upgrade

Equip X with any of the two arm upgrades

Equip X with the body upgrade

Equip X with the Ultimate Armor [Ultimate Armor usage will invalidate any other achievement]

Play as Black Zero

Get all the upgrades, hearts and tanks with X

Get all the hearts and tanks with Zero

Defeat Ereigon at Sky Lagoon Area 1

Cut Web Spider's web

Defeat Web Spider without using weapons, Nova Strike and learned techniques

Defeat Cyber Peacock without using weapons, Nova Strike and learned techniques

Defeat Storm Owl without taking damage

Defeat Magma Dragon without using weapons, Nova Strike, learned techniques and the Ride Armor

Defeat Jet Stingray without using weapons, Nova Strike and learned techniques

Defeat Split Mushroom without using weapons, Nova Strike and learned techniques

Defeat Slash Beast without using weapons, Nova Strike and learned techniques

Defeat Frost Walrus without using weapons, Nova Strike and learned techniques

Defeat Web Spider without taking damage

Defeat Cyber Peacock without taking damage

Defeat Storm Owl without using weapons, Nova Strike and learned techiniques

Defeat Magma Dragon without taking damage

Defeat Jet Stingray without taking damage

Defeat Split Mushroom without taking damage

Defeat Slash Beast without taking damage

Defeat Frost Walrus without taking damage

Defeat Snow Base Sub-Boss without taking damage

Defeat Colonel at the Space Port without taking damage

Playthrough Cyber Space Area 1 with Zero without using Kuuenbu (Rotating Saber) and only get S Ranks

Reach at the end of Air Force Area 1 with the Ride Armor

Get the Plasma Shot upgrade in Storm Owl stage and reach the boss door without ever activating the Stock Shot capsule

Defeat Magma Dragoon using only the Ride Armor

Complete Marine Base Area 1 without taking damage

Defeat Bio Laboratory Sub-Boss without letting him destroy more than 2 platforms

Defeat Military Train Sub-Boss in less than 5 seconds

Complete Space Port without using weapons, Nova Strike, learned techniques and dying

Complete Both Areas from Final Weapon Stage 1 without weapons [except when needed], Nova Strike, learned techniques and dying

Finish the Boss Rush without using weapons, Nova Strike, learned techniques, sub-tanks and dying

Defeat Sigma First Form without letting him using his dash attack

In one single run, defeat all the 8 Mavericks, collect all the hearts and tanks with Zero without revisiting any stage

Beat the game without upgrades, hearts and tanks