Here is the full list of all 50 Fetch achievements.
Watch The Game's Credits
Find the Witch Doctor
Surprise the Three Parrots
Rescue the Alligator
Launch the Crate
Make the First Mouse Sing
Drop the Hanging Crate
Beat Rainbow Snake Time
Rescued the Poodle in the Tunnel
Open Sewer Access Door
Enter the Hydrant
Pop Every Bubble
Beat Alien Shooter
Press All the Billboards
Push in all the Nails
Activate the Construction Equipment
Loosen all the Staples
Find your first love
Find the Dog Tag in the Grate
Win 1000 Gold in One Game of Pier Pressure
Sink Two Submarines in Pier Pressure
Rescue Iris from the P1R4T3
Feed the Bird
Take a Ride on the Tram
Buy Everything in the Vending Machine
Play the Organ Correctly
Beat Invaders with All Power-Ups
Feed the Shark
Find the Hidden Eel
Save Both Cavemen
Unearth Both Fossils
Find the Princess in the Castle
Fill the Egg Car
Fill the Mail Car while Train is on the Lower Track
Fry an Egg
Fire the Bullet Train Five Times
Quarantine all HOPA Viruses
View all of the Photos
Find the Dog Tag in the Robot's Chest
Power Robot's Core
Defeat the Alien Infestation
Ride in the Spaceship
Click McDivot Five Times
Get Captured by GU4RD5
Sneak by GU4RD5 on First Try
Fly Clean for 3000M
Destroy 30 Robots in 10 Seconds
Enter the Embark Lobby
Save Bear
Beat Fetch with a Score of 280,000,000