Here is the full list of all 40 YesterMorrow achievements.
Learn the second special ability
Cleanse 10 creatures
Throw a bomb at a NPC
Learn the first special ability
Beat the first boss
Pet 10 animals
Gain Eversight
Banish 20 Shadows with Bombs
Learn the third special ability
Learn the fourth special ability
Learn the fifth special ability
Learn the sixth special ability
Roll 500 times
Use all Timekeeper skills at least once
Beat the second boss
Beat the third boss
Beat the fourth boss
Beat the fifth boss
Beat the sixth boss
Beat the final boss
Restore the Conduit without the proper tools
Restore the Conduit using Timekeeper artifacts
Pet all domestic animals
Complete Forest island (story and collectibles)
Complete Desert island (story and collectibles)
Complete Ice island (story and collectibles)
Cleanse 50 creatures
Cleanse 150 animals
Pet 20 animals
Pet 30 animals
Expand your hit points to 7
Expand your hit points to 10 or more
Unlock all journal entries
Light up 50 Everlight lanterns
Banish 20 Shadows with Dash
Banish 20 Shadows with Megastomp
Banish 100 Shadows in one playthrough
Collect all map fragments
Collect 5 Timekeeper artefacts
Collect all Timekeeper artefacts