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