Here is the full list of all 18 Grow Up achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Throw 100 seeds whilst gliding
Take a Critter to the moon
Complete all challenges
Complete the game 100%
Collect all crystals
Blast a Critter 100m
Ride two Sporchids simultaneously for 400m
Discover the bull and the sheep
Plant 10 Champolines on top of each other
Unlock all Telerouters
Orbit the entire planet in BALL mode
Flower all STARPLANTS
Complete a challenge holding a Critter
Discover letter block P
Bounce on a Youch 7 times without touching the ground
Rescue MOM
Unlock all seeds
Visit all biomes