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