GreyWake: Project Somnium - Prelude is free to play, so its reviews count players rather than sales and there is no owners estimate. The Charts section shows who is playing.
No follower sample for GreyWake: Project Somnium - Prelude yet. The followers poller reaches every coming-soon game and the most played games daily; the count appears here with its first sample, and gains once a second sample the window back exists.