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