Unlockables
     Do  the following task to unlock the achievement 
and it's alloted gamerscore.

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

Go SP Yourself
     The  Barrier Magic has a field skill "Field Barrier 3" which only
costs  1  MP (instead of 10) at rank 50. Once you earn and assign this
skill,  you  can  venture  to  places  with  plenty  of enemies you've
defeated  before  and  simply  walk  into them with the Black Belt and
Eyepatch  accessories  (the  skills  Attract Aura and Regenerate MP at
this point are self-explanatory). Some good places would be:

Underground River - the Kelolon Defender Room
Primitive Cube - the Blazing Moths in teh garden
West Ice Field - the Roball racetrack

Secret Achievements for Blue Dragon
     This  is  a  list  of  the 18 secret achievements in the Japanese
version  of Blue Dragon. Complete each task to unlock the achievement.
Several of these achievements contain plot points, so read at your own
risk!

Complete Mechat Shooting Stage 2 perfectly - 30 points 
     Destroy  all  machine  guns on Mecha Base High and take no damage
while completing Mechat Shooting Stage 2.

Complete Mechat Shooting Stage 3 perfectly - 30 points 
     Complete Mechat Shooting Stage 3 without taking any damage.

Get Surprise Attacked 50 times - 0 points 
     Allow monster parties to attack you from behind 50 times.

Install all Mechat upgrade parts - 10 points 
     Obtain all nine Mechat upgrade parts and then install them all at
the Mechat Dock. You need not install them all at once.

Moon Laser Perfect - 30 points 
     Complete  the  Moon  Laser  mini-game  and  receive  the "Perfect
Bonus". (You cannot take damage or hit any of the moons for 0 damage.)

Obtain all dragon items - 10 points 
     Defeat  all  five  dragons and open the chests they leave behind.
This achievement unlocks when you obtain the fifth item.

Reach MAX rank for all of the Killer Bat's categories - 50 points 
     Reach  rank  99 in all nine categories for the Killer Bat shadow.
Do not use a heart item to go from rank 98 to 99 in any category.

Reach MAX rank for all of the Saber Tiger's categories - 50 points 
     Reach  rank 99 in all nine categories for the Saber Tiger shadow.
Do not use a heart item to go from rank 98 to 99 in any category.