Here is the full list of all 21 Rock of Ages 3: Make & Break achievements.
Defeat Moby Dick
Rescue the Dragon.
Defeat the Vitruvian Man.
Beat Poseidon in a race.
Get a bronze medal in all time trial levels.
Get a silver medal in all time trial levels.
Get a gold medal in all time trial levels.
Win a match of Boulder Avalanche or War without letting the enemy touch your door.
Win an online match of War.
Win an online match of Obstacle Race.
Complete all the Humpty Dumpty challenges.
Destroy the enemy boulder using the thundercloud.
Rate a map from the Community levels.
Collect all the stars from the story campaign.
Land in the highest scoring hole in the Skee-Boulder ramp.
Follow all of Napoleon’s directions in the level editor tutorial.
Earn the Squire's medal by climbing up in the ranking system.
Earn the Knight's medal by climbing up in the ranking system.
Earn the Lord's medal by climbing up in the ranking system.
Earn the King's medal by climbing up in the ranking system.
Earn the High King's medal by climbing up in the ranking system.