Here is the full list of all 40 Summer Catchers achievements.
Find all stashes (co-op only)
Buy all outfits, cars and postcards
Use a bell to wake up a sleepyhead
Collect 1000 rainy mushrooms
Listen to the whole inventory song
Chew some bubble gum (co-op only)
Play in co-op
Break down a car before a race (co-op only)
Help musicians to put on a great show
Complete all mailings
Tame all pets
Find the Firework Rocket
Tame a chameleon
Reveal the Crystal Skull
Tame a robot
Collect 1000 mushrooms from totems
Bucket the Meteorite
Tame a goat
Tame a fox
Find the Casette Player
Leave a race right after a crash
Tame a ferret
Win the Jar with fireflies
Catch a bubble, a drum and a horn in one race
Catch the World Map
Tame an owl
Activate a secret code
Receive the Bell
Overcome a hill or a bridge. No boosters, no bubbles
Overcome 5 obstacles in a raw in a bubble
Complete tutorial