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