Do the following task to unlock the achievement and it's alloted gamerscore.
Unlockable - How to Unlock
All Barriers Released (25) - Release all barriers
1,000,000 Gold Accumulated (25) - Accumulate 1,000,000 gold
100 Back Attacks (30) - Successfully pull off 100 back attacks
100 Monster Fights (30) - Set up over 100 monster fights
All Characters Level MAX (50) - Get all characters to level 99
All Warp Clip Set (25) - Activate all warp monuments
Dragon, 1 Category Rank MAX (30) - Max out the rank of one category for Dragon
Dragon, All Category Rank MAX (50) - Max out the rank of all categories for Dragon
Item Dictionary Complete (25) - Complete all entries in the item dictionary
Mechat Shooting, ST1, Perfect (30) - Clear Mechat shooting with no damage
Minotaur, 1 Category Rank MAX (30) - Max out the rank of one category for Minotaur
Minotaur, All Category Rank MAX (50) - Max out the rank of all categories for Minotaur
Monster Dictionary Complete (25) - Complete all entries in the monster dictionary
Phoenix, 1 Category Rank MAX (30) - Max out the rank of one category for Phoenix
Phoenix, All Category Rank MAX (50) - Max out the rank of all categories for Phoenix
Rare Item "Dragon Bracelet" (10) - Find the rare item Dragon Bracelet
Rare Item "Ultimate Conflict Necklace" (10) - Find the rare item Ultimate Conflict Necklace
Rare Item "Ultimate Weapon Bracelet" (10) - Find the rare item Ultimate Weapon Bracelet
Rare Monster "Gold Mecha Robo" (30) - Defeat Gold Mecha Robo
Rare Monster "Golden Unchi-Snake" (30) - Defeat Golden Unchi-Snake
Rare Monster "Ousama Unchi-kun" (30) - Defeat Ousama Unchikun
Simultaneous Encounter, Over 10 Parties (30) - Successfully pull off over 10 parties of simultaneous encounters and defeat all the monsters
Successful Back Attack (5) - Successfully pull off a back attack
Successful Simultaneous Encounter (5) - Successfully pull off a simultaneous encounter
Wagon Defense, Perfect (30) - Clear wagon defense with no damage