Here is the full list of all 51 Trine 2: Complete Story trophies - there are 42 bronze, 5 silver, 3 gold and 1 platinum.
Earn all Trophies in Trine 2
Kick five enemies of the same kind into a bottomless pit with the Thief's grappling hook kick or the Knight's Kitesail Shield glide kick
Construct a tower made of eight objects and stand on top of it
Shatter three frozen enemies within one second
Build a three-piece or three-character tower where lowest part is Pontius and his shield, tower must stand at least five seconds
Launch an object with Knight's magnetic shield and break it with hammer before the object touches the ground
Throw a box with Pontius' magnetic shield and catch it or have another player catch it
Complete the game on hard using hardcore mode
Glide for five seconds with Kitesail Shield while having an object or character on top of the shield
Complete a level with only Zoya
Complete a level with only Amadeus
Complete a level with only Pontius
Create a makeshift raft of three separate parts and have a goblin sail it for five seconds
Finish a level without taking any damage (except in the Story Begins)
Collect all experience pickups in the game
Complete Goblin Machinations
Complete the game
Complete Cloudy Isles
Find all chests in the game
Get at least 10 enemies killed by other enemies' actions in a single level
Capture a goblin in a Monster Prison and then launch it with a catapult
Complete Brackenridge Rise
Freeze two enemies and stack them on top of each other
Kill an enemy with a thrown hammer bouncing at least once before kill
Capture three different types of enemies inside boxes and stack them on top of another
Make a sandworm kill another sandworm
Shoot three arrows in the air and catch them all with the Knight's shield
Make a bubble sink for three seconds
Complete Belly of the Beast
Complete Deadly Dustland
Complete The Heroes Return
Kill a grenadier goblin with its own cannonball
Complete The Final Chapter
Kill an enemy with an airborne object tossed with the Knight's charge
Complete Icewarden Keep
Complete Eldritch Passages
Complete Searock Castle
Complete Mushroom Murk
Complete Mushroom Caves
Stand on a plank floating on a single airflow for four seconds
Stand on a conjured box bouncing on any bouncy surface for 10 seconds
Complete Hushing Grove
Using grapple, swing around an object and reattach grapple again without touching any surface
Feed carnivorous plants with three or more different kinds of treats
Complete Shadowed Halls
Complete Petrified Tree
Complete Mosslight Marsh
Complete Mudwater Dale
Complete Forlorn Wilderness
Make goblins die of three different environmental hazards in a single level
Complete The Story Begins