There are 12 Trophies that can be collected.

Bronze

Top Shot    
In SkeeBoulder, land your Boulder in the maximum multiplier.    

Eagle Eye    
Score a direct hit on an enemy boulder with the Castlepult.    

Rock the Boat    
Destroy a flying ship.    

Berserker    
Hit the castle gate with the fireball powerup.    

Prosperous    
Earn more than 7000 gold in one match.    

Escape from Hades    
Complete the tutorial level and escape from the underworld.

Champion of Champions    
Beat the game in Story mode.

Silver

Flawless Victory    
Win a match with your gate unscathed.    

Cocky    
Win a match without destroying any of your adversary's units.    

Keymaster    
Find all the keys scattered throughout the levels.

Troublemaker    
Win 10 online War games.

Gold

Bling Bling    
Get a gold medal on all maps in Time Trial mode.

http://www.ps3trophies.org/game/rock-of-ages/trophies/