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