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
Complete Cabin Ambush
Complete Invasion of Privacy
Complete 30 Minutes or Less
Unlock Steve
Unlock Erica
Complete Hospital Brawl
Found 25 hidden gnomes. Half-way there!
Unlock Will
Unlock Hopper and Joyce
Complete Chores for Granny Perkins
Successfully hack the hardest level chest/door
Unlock Eleven
Unlock Max
Complete Ivan the Smuggler
Complete Break In, Make Out
Complete Revenge of the Geeks
Acquire five trinkets
Complete Rats in the Walls
Complete Wall Flower
Unlock Jonathan
Unlock Nancy
Complete Store Raid
Complete On the Wire
Complete Radar Love
Crafted your first item
Unlock Dustin
Complete Sneak Peek