Here is the full list of all 37 Mega Man Zero/ZX Legacy Collection achievements.
Complete all stages in Z Chaser (including hidden stage).
Complete Mega Man Zero, Zero 2, Zero 3, Zero 4, ZX, and ZX Advent.
Complete Mega Man ZX Advent (cannot be earned in Casual Scenario Mode).
Defeat a boss in Grey's Reploid form or Ashe's Human form in Mega Man ZX Advent.
Obtain at least one of each bronze, silver, and gold medals in Mega Man ZX Advent.
Obtain all 4 subtanks in Mega Man ZX Advent.
Copy an enemy's data for the first time in Mega Man ZX Advent.
Complete Mega Man ZX (cannot be earned in Casual Scenario Mode).
Defeat Omega in Area N in Mega Man ZX (cannot be earned in Casual Scenario Mode).
Obtain all Item B chips in Mega Man ZX.
Obtain a biometal with a Lv. 4 victory in Mega Man ZX.
Obtain a W Tank in Mega Man ZX.
Double Megamerge after inheriting Model Z in Mega Man ZX.
Complete Mega Man Zero 4 (cannot be earned in Casual Scenario Mode).
Defeat Craft in the Ragnarok Control Room and stop Ragnarok in Mega Man Zero 4.
Defeat a boss with three Junk chips equipped and without a cyber-elf equipped in Mega Man Zero 4.
View 30 cards across all six titles in the Gallery, then change the wallpaper to the secret image.
Create an S-Crystal in Mega Man Zero 4.
Create a chip by combining collected parts in Mega Man Zero 4.
Complete Mega Man Zero 3 (cannot be earned in Casual Scenario Mode).
Defeat Phantom in Cyberspace in Mega Man Zero 3 (cannot be earned in Casual Scenario Mode).
Obtain all body chips in Mega Man Zero 3.
Defeat Copy X Mark II in Mega Man Zero 3.
Cut off Blazin' Flizard's tail in Mega Man Zero 3.
Exit Cyberspace after experiencing it for the first time in Mega Man Zero 3.
Complete Mega Man Zero 2 (cannot be earned in Casual Scenario Mode).
Intercept the bombardment aircraft in Mega Man Zero 2.
Obtain the X Form in Mega Man Zero 2.
Use an EX Skill to score the final hit against any boss in Mega Man Zero 2.
Outrun the ghost for the first time in Z Chaser.
Defeat Gazamir in Mega Man Zero 2.
Listen to 3 tracks from each album in the Music Player, then beat any game and listen to its ending theme.
Complete Mega Man Zero (cannot be earned in Casual Scenario Mode).
Destroy the ice dragon summoned with Leviathan's "Spirit of the Ocean" EX Skill in Mega Man Zero.
Listen to all of Andrew's monologues to the end in Mega Man Zero (cannot be earned in Casual Scenario Mode).
Enter Ciel's room at the base in Mega Man Zero.
Complete the opening stage in Mega Man Zero.