Here is the full list of all 38 Psychonauts trophies - there are 21 bronze, 12 silver, 4 gold and 1 platinum.
Unlock all trophies.
Revisit all brains after completion.
Complete Meat Circus.
Achieve Rank 101.
Sort all Emotional Baggage.
Gather all Figments.
Crack all Vaults.
Introduce all Camp Kids to Mr. Pokeylope.
Re-brain the Children.
Complete The Asylum.
Complete Black Velvetopia.
Find all Golden Helmets.
Earn all Merit Badges.
Find Edgar's Secret Garden.
Complete Waterloo World.
Complete Gloria's Theater.
Achieve Rank 80.
Redeem all 16 Scavenger Hunt Items.
Complete The Milkman Conspiracy.
See yourself through the eyes of many others.
Complete Lungfishopolis.
Achieve Rank 60.
Hear Vernon's Ghost Story.
Spy on Bobby's love life.
Complete Milla's Dance Party.
Uncover Milla's Secret.
Achieve Rank 40.
Complete Sasha's Shooting Gallery.
Achieve Rank 20.
Witness Maloof's transformation.
Cook and consume two different kinds of roast in one sitting.
Use the bacon. A lot.
Give the Coach's speech on the stump.
Buy an item from the Camp Store on Christmas.
Read many bulletin board messages.
Discover the secret history of Whispering Rock.
Complete Basic Braining.
Complete the Punchy Target mini-game.