Treyarch and Activision haven't been shy about the fact that the Xbox 360 and PlayStation 3 versions of Call of Duty: Black Ops 3 will be quite different from the Xbox One and PlayStation 4 versions. If you're a bit salty over the difference between the last-gen version and current-gen, there's something to be aware of – Beenox, a subsidiary of developer for Activision, has been the one busy porting the game to older consoles – not Treyarch.
The Black Ops 3 campaign could not effectively run on the older consoles, due to Treyarch's "ambitious" vision, so it was cut. On top of that, the game will run at 30FPS on the last-gen versions, instead of 60FPS like on the Xbox One and PS4.
According to Beenox creative director Thomas Wilson, the developers have been peeling away the layers of the Xbox One and PS4 version to make it work on PS3 and Xbox 360. “What we do is we basically, step by step, reduce the polycounts on each asset, reduce the amount of memory that each effects will take, and then eventually we make sure that we maintain that core experience intact."
Well, they definitely reduces quite a bit on the PS3 and Xbox 360 version, quite a bit indeed. Check out a comparison of the Xbox One version against the Xbox 360.