Here is the full list of all 33 Cloud Knights achievements.
Failed the first mission.
Fell down with full health.
Finished a mission in two player co-op.
Reached a killstreak of four or more enemies.
Finished a campaign mission with one of two players dead.
Finished a mission with all players in full health.
Failed a mission with only one enemy or flaming skull away from victory.
Defeated the Undead Champion in mission 15.
Defeated the Undead General in mission 30.
Defeated the Necromancer Knight in mission 45.
Defeated the Awoken Beast in mission 60.
Destroyed 50 boxes, barrels or chests in a single campaign mission.
Caused ten critical hits using a scimitar in a single campaign mission.
Caused ten critical hits using a broad sword in a single campaign mission.
Caused ten critical hits using an axe in a single campaign mission.
Caused ten critical hits using a double blade in a single campaign mission.
Caused ten combo hits using a scimitar in a single campaign mission.
Caused ten combo hits using a broad sword in a single campaign mission.
Caused ten combo hits using an axe in a single campaign mission.
Caused ten combo hits using a double blade in a single campaign mission.
Got five separate killstreaks in a single campaign mission.
Won a versus duel 3-0.
Lost a round of a versus duel with full health.
Won a versus duel after the other player was ahead by two stars.
Pushed ten enemies off a platform in a single campaign mission.
Collect three stars in every mission of Chapter One.
Collect three stars in every mission of Chapter Two.
Collect three stars in every mission of Chapter Three.
Collect three stars in every mission of Chapter Four.
Gain three stars on all missions from 1 to 60.
Survived for 5 minutes in Survival Mode.
Survived for 10 minutes in Survival Mode.
Survived for 3 minutes in Survival Mode.