Only third party I can think of not on steam is FF16, Rebirth, bayonetta (2+3) and Unicorn overlord. Granted all those games will hit steam, outside bayonetta 2+3. Not sure what major third party steam doesn't have.
Edit
Bloodborne and Demon are missing from steam. Though I hope Demon Remake finds it's way at some point.
Last edited by Chrkeller - on 15 March 2024