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