I will start with the one negative I have just to get that out of the way:
The port was rough, as most Sony ports are. The game runs OK, on Ultra 1440p my PC was struggling to break 60fps. I instead played on the original settings which yielded about 140+ fps in empty terrains, but 50-70 fps in cluttered areas. If you use MnK, the controls can be very clunky at times.

Now onto the real review:
Horizon Zero Dawn is easily one of my most favorite games of all time. I finished the game in about 50 hours, and every step of the way had me fully engaged. There is SO MUCH to do in this world, so many side quests that all have incredibly interesting and branching story lines. The main story takes you all around Horizon Zero Dawns massive open world, but leaves a lot for you to discover and interact with on your own.
The game play is exhilarating. I've never been a fan of bow and arrow weapons in any game, but being your main weapon in Horizon Zero Dawn the devs did a fabulous job at not only making the fighting mechanics fun and smooth, but they give you a wide array of options for things like ammo and modifications. This allows you to approach fights in many different unique ways. I think most players can find a preferred method of attack for most machines.
There's a lot of good things I have to say about Horizon Zero Dawn, but I think it is best experienced. I do think this game is worth its $50 price tag, but it does go on sale often. I picked it up for only $13 during a Sony sale.