Final Fantasy 13 Unlocks
Pulsian Pioneer - 15 G (Bronze) - Walk 10,000 steps on the surface of pulse, then talk to Pacti.
Gysahl Wreath - 15 G (Bronze) - Using the chocobo dig mini game, dig up a ribbon.
Kelger's Cup - 15 G (Bronze) - Complete all D-rank Cie'th Stone missions, i.e. Missions 1-5.
Xezat's Chalice - 15 G (Bronze) - Complete all C-rank Cie'th Stone missions. The list is: 6-15, 18-22, 28, 35-37, 39, 56, and 57.
Commando's Seal, Ravager's Seal, Sentinel's Seal, Saboteur's Seal, Synergist's Seal, and Medic's Seal. - 15 G (Bronze) - For each of these six achievemnts, you must max out the Crystarium for that role on one character. It doesn't matter what character. You cannot complete these until you have beaten the game, as the final Crystarium level is only unlocked with clear data.
Master's Seal - 30 G (Silver) - Fully max out the Crystarium for all six roles, for all six characters. Read later in this guide for tips for grinding the CP necessary!
Exorcist - 30 G (Silver) - Complete Missions 7, 12, 27, 30, 34, 51, and 64. These seven battles pit you against the Undying, which are powerful Cie'th monsters.
Floraphobe - 30 G (Silver) - Complete Mission 54, which pits you against the Jumbo Cactuar.
Natural Selector - 30 G (Silver) - Complete the Titan's Trials, i.e. Missions 35-51.
Dorgann's Trophy - 30 G (Silver) - Complete all B-rank Cie'th Stone Missions. The list is: 16, 17, 23-27, 29-34, 38, 40, 42, 43, 47, 50, 54, and 58.
Galuf's Grail - 30 G (Silver) - Complete ALL Cie'th Stone Missions. You do not need any specific star ranking to obtain this achievement.
Limit Breaker - 30 G (Silver) - Deal 100,000 damage with one single attack. To do this you need the Genji Gloves. If you do not have them, your characters are limited to 99,999 damage with a single blow. Eidolons, however, are not limited, so it is possible to use a high powered Eidolon attack to break the limit. Fang with Highwind is good for the Genji Glove method. Bahamut's Mega Flare is good for the Eidolon method.
Adamant Will - 30 G (Silver) - Defeat a Long Gui. Describing how to do this would take an exceptionally long time, but for a general idea, check out this youtube video.
L'cie Paragon - 80 G (Gold) - Complete ALL Cie'th Stone Missions with a 5-star rank. Pressing X on the 360 or Square on the PS3 while in the Map Menu lets you see all of your missions and what ranking you've gotten on them. This achievement unlocks Snow's gamer pic for the 360 and his XMB theme for the PS3.
Treasure Hunter - 80 G (Gold) - At some point in the game have held every weapon and accessory. You do NOT need to have them all at once. You do NOT need to have every variant of each ultimate weapon. There are many accessories that you cannot find more than once, so selling your items is not advised. The Survivalist Catalog, the Gold Watch, and the Champion Badge are all items that you should not evolve, because they evolve into other items that are more common. Note: This achievement unlocks Fang's Gamer Pic for the 360 and her XMB theme for the PS3.
Loremaster - 80 G (Gold) - Reveal the full datalog page for at least 100 enemies. Between fighting some enemies dozens of times, using Libra often, and the sheer number of different enemies in the game, this achievement is no trouble at all. This achievement unlocks Sazh's gamer pic for the 360 and XMB theme for the PS3.
Superstar - 80 G (Gold) - 5-star the final form of Orphan, the final boss. You can always come back to fight Orphan again after beating the game, so don't worry about doing it the first time around. This achievement unlocks Lightning's gamer pic for the 360 and her XMB theme for the PS3.
For unlocking all achievements, you unlock Serah's gamer pic on the 360 and her XMB theme, as well as the Platinum trophy, for the PS3.