Here is the full list of all 37 Timespinner achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Acquire every Orb Spell.
Acquire every Orb Passive.
Finish all character quests.
Discover 100% of the map.
Collect all Downloads.
Collect all Memories, Letters, and Downloads.
Find all Melee Orbs.
Defeat the Ravenlord in battle. (Normal or Nightmare mode only)
Defeat Ifrit in battle. (Normal or Nightmare mode only)
End the War of Sisters before any blood is shed.
Defeat Nightmare in battle. (Normal or Nightmare mode only)
Defeat the Sandman in battle. (Normal or Nightmare mode only)
Defeat the ruler of Lachiem.
Defeat Emperor Nuvius in battle. (Normal or Nightmare mode only)
Collect all Memories.
Defeat Xarion in battle. (Normal or Nightmare mode only)
Defeat Genza in battle. (Normal or Nightmare mode only)
Defeat a boss without stopping time nor taking damage.
Defeat Cantoran in battle. (Normal or Nightmare mode only)
Finish a character's entire quest line.
Have an Alchemist make you a new Spell.
Have an Alchemist make you a new Passive ring.
Defeat The Maw in battle. (Normal or Nightmare mode only)
Collect all Letters.
Defeat Aelana in battle. (Normal or Nightmare mode only)
Defeat the Golden Idol in battle. (Normal or Nightmare mode only)
Finish a character's quest.
Defeat the Azure Queen in battle. (Normal or Nightmare mode only)
Defeat Varndagroth in battle. (Normal or Nightmare mode only)
Find a new Melee Orb.
Defeat the Feline Sentry in battle. (Normal or Nightmare mode only)
Find your first Familiar companion.
Achieve all possible feats on the same save file.
Prevent the Qaelans from being persecuted by the Empire.
Beat the game on Nightmare mode.
Collect all Familiar companions.
Obtain an Orb without breaking its pedestal.