Once upon a time, when the Playstation 2 reigned over all, Guerrilla Games(known as SCE Cambridge Studio at the time) released a game called Primal. The game quickly gained a cult following for its combination of interesting game mechanics, at-the-time stunning graphics, fluid combat, entertaining story and likeable characters, selling 430,000 copies worldwide.

Now, shortly after it released, Guerrilla Games began working on a sequel to this frankly amazing game but they dropped it, having just acquired licensing rights to make 24: The Game(which ironically sold 130,000 less copies than Primal).

Sadly, Guerrilla Games never returned to work on Primal 2, despite having explored two possibilities for the sequel and having developed some very interesting concept art.

That brings us up to now. The Playstation 4 is supremely powerful, able to compete with mainstream PC gaming and is supremely popular to boot; It's the perfect base for Primal 2 to become a reality.

Primal 2, if held to the same standards as it's predecessor could likely compete with games such as Uncharted 4, whilst taking players back to the nostalgic times when we could have great graphics and amazing gameplay.

sources:
https://en.wikipedia.org/wiki/Primal_(video_game)
https://www.unseen64.net/2015/05/11/primal-2-ps2-c...
http://www.vgchartz.com/game/1787/primal/