Here is the full list of all 34 Final Fantasy VIII Remastered achievements worth 1,000 gamerscore.
Finish the game
Complete the Obel Lake side quest
Beat the Omega Weapon
Kill 1000 enemies
Collect all Timber Maniacs magazines
Complete the PuPu side quest
Unlock Guardian Force Eden
Unlock Guardian Force Bahamut
Unlock Guardian Force Cactuar
Find Ragnarok
Unlock Guardian Force Doomtrain
Draw magic 100 times from draw points
Reach maximum HP
Unlock Guardian Force Alexander
Unlock Guardian Force Cerberus
Unlock Guardian Force Pandemona
Unlock Guardian Force Tonberry
Capture a Chocobo
Defeat every member of the CC group
Reach SeeD rank A
Unlock Guardian Force Leviathan
Unlock Guardian Force Carbuncle
Unlock Guardian Force Brothers
Draw (Stock) magic from enemies 100 times
Upgrade your weapon
Kill 100 enemies
Lose a rare card in a Triple Triad game
Play Triple Triad
Unlock Guardian Force Diablos
Get your first salary from SeeD
Unlock Guardian Force Siren
Unlock Guardian Force Ifrit
Unlock Guardian Force Shiva
Unlock Guardian Force Quezacotl