This trophy is kind of bugged.
To get it you have to be the host of the game - this is a key enabler!
1. From you lobby invite another player.
2. Start playing below 20 levels.
3. Wait till you both will be on the begging of the level and try to both finish the level.
4. the two last level my partner dies at the end and I still get this trophy.
Level needed to be completed are:
Prologue
Introduction
Needlepoint Peaks
Newton's Airship
Stitchem Manor
Tinpot Towers
Book One: Manglewood
High Stakes Heist
Deep Space Drive-In
Shake, Rattle, and Roll
Crumbling Crypts
Light, Camera, Traction!
Book Two: The Ziggurat
Furry Soles, Hot Coals
Flip-Flopped Folios
Go Loco
Tutu Tango
On the Links of Disaster
Book Three: Bunkum Lagoon
Belly of the Beast
Masque Maker's Tower
Cloud Caravan
The Great Escape
Even Bosses Wear Hats Sometimes...
Good Luck!