Sony Santa Monica confirmed a new God of War in December 2014. We had to wait one year a half to see it for the very first time as it wowed us at E3 last summer. But, between God of War Ascension and the reboot of the saga for PlayStation 4, the company was designing a new IP that wound up getting cancelled.
Thanks to Nerdleaks, the source that spoiled Microsoft's pre-E3 conference, we now know more about this game and get a glimpse of what never came to be in artworks. Theses were found in Erik San Juan portfolio, a game developer & 3D concept designer who was working at Sony Santa Monica up until April 2014.
It was meant to be a futuristic game, maybe set in near future because there is something called "Ark Mission Genesis - A.D. 2034". This universe is populated by almost every creature you can image: aliens, drones, hueg "dinosauresque" animal, and also a lot of different humans.
This game with no name was cancelled and most of talent working on it laid off, so we will most likely never get to see it on PS4. But you can take a look at the arworks here.