The first game was one of my favorite games to play ever. It had a great and interesting story full of compelling characters that drove me to want to finish it.
Forbidden West suffers from being a sequel, as it continues on from the previous games story. However, I feel that the most interesting aspects of exploring the post-apocalyptic world were fleshed out and explained in the initial story arc and leave little new to discover.
The machines are essentially the same as before, with minor tweaks. The characters you meet have dull story arcs that all revolve around fetch quests of some sort.
The graphics are amazing, and account for most of this rating. That is, when Aloy's snake/tentacle hair isn't flailing all over the place, or when the glitchy jumping/climbing allows for yourself and NPCs to get stuck inside mountains (which has happened multiple times - once not allowing me to finish a quest and forcing me to restart from an earlier save).
Overall: It's a decent game, not worth its current price and I would definitely recommend waiting until it goes on sale in the future.