There are 12 Trophies that can be collected.

Bronze

Lifeguard    
Bring a comrade back from the dead.     

Slick Kick    
Defeat a boss using sliding.     

Bone Cold Justice    
Defeat an enemy by hitting back a Skeleton's bone.     

Grim Synergy    
Defeat a boss using a Dual Crush.     

Poetic Justice    
Defeat an ally who has been seduced by the enemy.     

Vampire Hunter    
Destroy the lord of Castlevania.     

Grasshopper    
Jump kick 30 times in a row without touching the ground.

Silver

Boned    
Defeat a boss with 5 players in skeleton form.

Pack Rat    
Collect a large number of items.    

Wicked Deep Pockets    
Amass 1,000,000 gold.     

Slaughtervania    
Rack up 10,000 enemy kills.

Gold

Hunter Legend    
Complete Hard Mode.

http://www.ps3trophies.org/game/castlevania-harmony-of-despair/trophies/