Here is the full list of all 32 Stranger Things 3: The Game trophies - there are 16 bronze, 10 silver, 5 gold and 1 platinum.
Unlock all trophies
Beat the game on New Game+
Complete the game
Complete Mall Showdown
Found all 50 hidden gnomes
Found 25 hidden gnomes. Half-way there!
Complete Cabin Ambush
Complete 30 Minutes or Less
Unlock Steve
Unlock Erica
Complete Rats in the Walls
Complete Invasion of Privacy
Complete Ivan the Smuggler
Unlock Will
Acquire five trinkets
Complete Hospital Brawl
Complete Store Raid
Complete Wall Flower
Complete Revenge of the Geeks
Unlock Hopper and Joyce
Complete Chores for Granny Perkins
Successfully hack the hardest level chest/door
Unlock Eleven
Unlock Max
Unlock Jonathan
Unlock Nancy
Complete On the Wire
Complete Break In, Make Out
Complete Radar Love
Crafted your first item
Unlock Dustin
Complete Sneak Peek