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