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