Here is the full list of all 39 1971 Project Helios trophies - there are 30 bronze, 3 silver, 5 gold and 1 platinum.
Unlock all other trophies
Reach the three Endings (and complete the three Epilogues)
Reach Ending 3 (and complete its Epilogue)
Kill 200 Kaphirites
Kill 200 Wintersöhne
Alina killed 50 enemies
Read all Campfire dialogues
Wilhelm killed 50 enemies
Kill 200 Scavengers
Kill 3 or more enemy units with a single grenade
Use a grenade to remove stun from an ally unit
Domi killed 50 enemies
Alexei killed 50 enemies
Reach Ending 2 (and complete its Epilogue)
Reach Ending 1 (and complete its Epilogue)
Finish the game for the first time
Kill the Master
Shot 20 tiles away.
Kill 100 Kaphirites
Ame killed 50 enemies
Find all documents in the game
Kill all the Blades
Renzo killed 50 enemies
Kill a Blade
Finish level 7 with Wilhelm in your squad
Émile killed 50 enemies
Kill 100 Wintersöhne
Wait 4 minutes without doing any action in your turn (in combat)
Pet Ricotta in the Campfire
Kill 30 Kaphirites
Do "Overwatch + Push" combo 5 times
Hanna killed 50 enemies
Use fulgor to defreeze, decrease cooldown. and reanimate (in the same combat)
Kill 100 Scavengers
Kill 30 Wintersöhne
Find the Fulgor Tank
Lose and replay the same combat 3 times
Kill 30 Scavengers
Complete Level 1