Here is the full list of all 35 Fallout Shelter achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Make 25 babies
Collect 20 Legendary Dwellers
Craft 1 of every room theme
Collect 20 Legendary weapons
Scrap 500 items
Complete 100 objectives
Collect 20 Legendary outfits
Complete 100 Quests
Successfully stop 50 Raider Attacks
Craft 10 Weapons
Change the appearance of 10 NPCs in the Barbershop
Craft 10 Outfits
Build 1 of every room type
Complete 60 Quests
Collect all Pieces of 4 Themes
Craft an Outfit, a Weapon and a Theme
Upgrade 20 Rooms to Level 3
Collect 100 Stimpacks and 100 Radaway on Quests
Collect all Pieces of 1 Theme
Successfully complete 50 Room Rushes
Complete 30 Quests
Make 25 Dialogue Choices in Quests
Kill 500 enemies on Quests
Level up a Dweller to level 50
Build 50 rooms
Complete 10 Quests
Level up a Dweller to level 25
Kill 10 Quest Bosses
Level up a Dweller from 1 to Level 10
Build 25 rooms
Collect 10,000 Caps
Merged 3 Water Rooms
Merged 3 Food Rooms
Collect 1000 Caps
Merged 3 Power Rooms