Here is the full list of all 12 Monster World IV trophies - there are 9 bronze, 2 silver and 1 gold.
Collect all the Life Drops.
Finish the game.
Find the "Welcome to Monster World" message.
Rescue the Wind Spirit.
Rescue the Sun Spirit.
Wash your face in the spring at the Pyramids.
Rescue the Moon Spirit.
Rescue the Earth Spirit.
Collect 777 gold and see what happens.
Just started and you're already falling in pits!
Land 3 consecutive downthrusts without touching the ground.
Watch the SEGA logo sequence.