Here is the full list of all 12 Vandal Hearts: Flames of Judgment achievements worth 200 gamerscore.
Find a hidden item on any battlefield.
Execute a Team Attack.
Win a battle with 6 surviving party members.
Discover an optional battle map.
Finish Act I.
Finish Act II.
Finish Act III.
Finish Act IV with the Altyria ending.
Finish Act IV with the Luce ending.
Raise a weapon skill to rank 25.
Earn both endings to the game.
Discover every battle map.