Here is the full list of all 12 Letter Quest Remastered trophies - there are 7 bronze, 4 silver and 1 gold.
Spell 3000 words
Earn 40 crystal stars
Earn 120 yellow stars
Defeat 250 monsters
Do 100 critical attacks
Purchase 30 upgrades
Purchase 50 merchant items in battle
Complete 50 quests
Spell 3 words with no vowels
Use 25 plague tiles
Open 10 treasure chests
Finish a stage with full health