Here is the full list of all 19 Rock of Ages achievements.
Destroy your adversary’s boulder.
Break off the second layer of your adversary’s boulder.
Score a direct hit on an enemy boulder with the Castlepult.
Hit the castle gate with the fireball powerup.
Break off the first layer of your adversary’s boulder.
Complete the tutorial level and escape from the underworld.
In SkeeBoulder, land your Boulder in the maximum multiplier.
Destroy a flying ship.
Earn more than 7000 gold in one match.
Win a match with your gate unscathed.
Win a match without destroying any of your adversary's units.
Find all the keys scattered throughout the levels.
Beat the game in Story mode.
Get a gold medal on all maps in Time Trial mode.
Win 10 online War games.
Win an online War game
Land a projectile on some TNT to produce a shockwave combo that hits your enemy.
Win a match using the Snowball boulder.
Win a War game using the Cube.