There are 12 Trophies that can be collected.

Bronze

Welcome to Monster Land    
Read the "Welcome to Monster Land" sign.    

Ghost Slayer    
Defeat a resilient Ghost.    

You are O.K.    
Get a PERFECT for clearing a stage.    

Spell Master    
Use every type of magic.    

Music Maker    
Play the flute somewhere with a view.    

You have become really sturdy!    
Increase your LIFE to a max of 10 hearts.    

Lost and Found    
Obtain equipment from a defeated enemy.    

Gold in the Clouds    
Find all the gold hidden in the clouds of Round 7.    

Treasure Hunter    
Find 20 hidden items and/or gold.

Silver

Question: Who defeated me?    
Defeat the Sphinx.    

You are a True Hero    
Obtain all the Legendary Equipment.

Gold

Congratulations!    
Clear the game without using any continues.

http://www.ps3trophies.org/game/wonder-boy-in-monster-land/trophies/