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