Horizon: Zero Dawn is an absolute blast. It's difficult, but not impossible, on the normal difficulty setting, and at around 40-50 hours never gets old or repetitive due to the changing settings and variety of enemies you have to face.
One of the most intriguing video games stories I have ever encountered is in this game. You play as an outcast with no idea why you have been outcast from society or who your parents are. The world setting makes it clear that we are in the future, yet society has reverted back to an almost primitive state, albeit with some interesting holdover technology from whatever society must have been like in the game before it reverted to what it manifested into in the game. You go about looking for an understanding of who you are and where you came from, but the much more interested aspect in my opinion is finding out what happened to earth, and the story of corporate corruption and greed gone hawywire really resonated with me and compelled me forward throughout the game. It has it's cheesy and groan-inducing lines for sure, but the overall world-building and learning the history of how the world came to be the way it is was an absolute joy to discover.
You are essentially a hunter, who goes about a world infested with creatures that resemble actual creatures from the real world but are robots. They each have unique weak spots where you can aim and cause significant damage or disable their weapons. The battles change significantly depending on what kind of creature you are fighting. Sometimes you are fighting what appears to be a lowly horse, who generally won't attack unless you get too close or piss it off. Those are much easier to fight and conquer than, say, a giant t-rex robot who can kill you about a dozen different ways in essentially one hit.
You also get traps and wires, as well as the ability to collect resources from the world where you can craft potions and other items that can assist you in the fights against the robot-monsters. Sometimes you can choose to simply sneak by entire sets of enemies instead of engaging, but the parts you collect from the deceased robots are also crucial to upgrade your health, your ammo, and your weapons. The game gives you a lot of freedom of how you want to play, whether it's stealthily luring enemies one by one and taking them out or just running straight into a group and fighting like hell. Either way, the bow and arrow and ability to slow down time make shooting continuously fun and it never got old. The close-quarters combat, however, it clunky and it never quite felt like I was doing anything other than Dynasty-warriors' style mashing a button over and over to hit an enemy in the face.
My only other complaint in the game is that the climbing mechanics are frustrating. It's not always clear where you can climb and where you cant, and finding the exact spot that you are able to climb can take forever and is extremely time-consuming and annoying when you know you need to get to the top of a tower or building. Your main character also mumbles truly ridiculous and repetitive lines to herself throughout the adventure, which got old after approximately 12 seconds.
Other than that, I don't have many complaints about the game. The combat is fun, the game is rewarding, and the plot/world are maybe the best I've ever seen in a video game. The graphics are gorgeous and the environments change drastically depending on what part of the world you are in.
And the world is very large. It can take forever to get around but there are fast travel packs you can use to travel to locations you have been to before, which is super helpful as the world is filled to the brim with robot monsters. There are also little dungeons you can go into that, once completed, allow you to "override" certain robots, which basically means you mind-control them to your side and you can ride around on a robot horse or have a robot panther attack other enemies on your behalf, giving you the edge in battle. My favorite part of the game was the giant "Tallnecks," robot giraffes that you have to find a way to climb up. Once you climb them, it unlocks areas of the map you haven't been to before and is just a joy to take out enemies and climb up to get a great view of your surroundings. All of this is optional, and the game has so many more collectibles that could take you around 100 hours to fully complete the game if you are a true completionist.
Overall, I absolutely loved Horizon: Zero Dawn and recommend it to anyone who wants to play an action/RPG hybrid with a great world, awesome story, and fun combat.