Here is the full list of all 32 The Valiant achievements.
Kill an enemy Squad who is retreating.
Kill your first enemy Squad.
Complete your first single player campaign mission.
Complete the Prologue missions called Brothers and The Severance.
Unlock an Ability on a Hero's skill tree.
Use an item for the first time.
First use of Retribution.
Finish a mission with one challenge completed.
Finish a mission with all 3 challenges completed.
Complete 3 missions on hard difficulty.
Start a mission from the single player campaign, with Reinhard carrying the rarest armour or weapon.
Destroy 500 enemy Squads.
Defeat 20 enemy Squads as part of an ambush attack.
Charge at 20 different enemy Squads.
Insult 30 different enemy Squads.
Slow down 300 enemy soldiers using Volley Ability.
Consume 5,000 Vigour from using Abilities.
Form a bond with 10 different friendly Squads.
Destroy 5 buildings or siege engines.
Immobilize 50 enemy Squads.
Cancel out enemy's charge 10 times.
Collect all gear from one mission.
Collect all gear during a campaign.
Defeat a boss on hard difficulty.
Build a siege engine.
Knock down an enemy Squad using a siege engine.
Build 3 towers.
Unlock all skills of a Hero.
Complete campaign on easy difficulty.
Complete campaign on normal difficulty.
Complete campaign on hard difficulty.
Unlock all achievements from The Valiant campaign.