Here is the full list of all 14 ROTA achievements.
Discover grass
Discover grassy night
Discover cobblestone
Discover cobblestone day
Discover desert
Discover desert night
Discover snow
Discover snowy night
Collect 50 gems
Finish in under an hour
Clear the First Loop in "Wrap It Up"
Collect your first Gem
Collect your first Clock
Collect 50 Clocks