Here is the full list of all 35 Time on Frog Island achievements.
Complete the game within 5 (in-game) days
Obtain the Ice Herb before opening the mountain door
Leave the island in your fixed boat
Complete every quest and fully build your house
Knock over all of the carefully stacked stones in a day
Stay airborne for 7.5 seconds
Proudly display a honeycomb in your house
Pay The Carpenter to build all three stages of your house
Complete the frog statue ritual
Duplicate a coin by farming it
Replace your broken rudder with a new one
Complete all of The Cartographer's quests
Purchase something from the merchants shop
Replace your torn rope with a new one
Replace your broken wheel with a new one
Replace your ripped sail with a new one
Complete the tavern questline before accepting any boat pieces
Take your pet plant to the western island to see the Dodos
Take your pet plant to see all the sights
Take your pet plant up the mountain to see the northern lights
Throw an item then grab it with your tongue before it hits the ground
Throw 1000 items
Jump 1000 times.
Grow every bounce mushroom on the island
Catch your first fish
Take your pet plant to the western island to see the ruins
Find and complete the hidden time trial
Sleep in every camp
Take your pet plant to the eastern island to see the strange ruin
Brew your first potion
Take your pet plant into the town to see the frogs
Speak to every frog on the island
Ask a frog about the same item 3 times in a row
Walk 10km
Evaluate the damage from the storm