Quark

Quark was a cancelled Dreamcast, PlayStation 2, and PC game by Quantic Dream. This was to be a 3D action-adventure title.

Plot
Quark was to be set in two parallel universes. One was a fantasy world named Quark and the other was 19th century London. Whatever you do in one universe affected the other.

Gameplay
You would play as either Waki or Una. Waki is the main protagonist and is an adventurer, looking for his sister Una. Una is a young orphan lost in London.

They both control animals; Una with dog and bird, Waki with fantasy animals. Both these characters have met in dreams but have never met before.

Development
Soon after release The Nomad Soul, Quantic Dream got to work on Quark. This game was to be more light-hearted and full of fantasy.

Quark Dreamcast Magazine issue 9 (May 2000) Dreamcast Magazine issue 9 (May 2000)

Cancellation
Quark only spent 8 months in pre-production before being cancelled. Quark was likely cancelled as Quantic Dream got more involved in the development of Fahrenheit. Quantic planned to return to Quark but by the time of Fahrenheit's release the concept was too dated, so it was dropped.

Video
Trailer.