Horizon Zero Dawn PC Mouse and Keyboard Controls
I am 15 hours into Horizon Zero Dawn on the PC. Before I started the game, I was still considering whether to use mouse and keyboard, or a controller. So I read up on it, and mouse and keyboard was recommended, due to the greater ease of aiming. And that has been working quite well for me at the start of the game. Most of the time the keys you can press are helpfully displayed on the screen. And while I must have missed the part of the tutorial where it told you that you can roll with LeftCTRL, that information was easy to find in the settings, under Control Mapping. But then I got a new weapon, a sharpshot bow, which came with a tutorial mission to hit three watchers in they eye, and I had great difficulty with that quest. My arrows were flying wide all the time, even from rather short distances. What was wrong? It turned out I hadn't fully understood the controls of shooting a bow.
Normally in the PC version of Horizon Zero Dawn, you hold the right mouse button to get into aim mode, and then you click the left mouse button to fire an arrow. If you have a fast bow, you can loose multiple arrows by clicking the left mouse button in fast succession, which works great if your target is relatively close to you. What I hadn't noticed was that you can also hold the left mouse button for a while, and then the arrow releases when you release the mouse button. There is a badly visible circle of light around your aim circle which gets smaller when you hold the left mouse button. And to be very accurate, like for example with the sharpshot bow, that is exactly what you need to do. Hold both mouse buttons while aiming for the eye, then let go of the left mouse button to shoot the watcher.
That took me a while to figure out, and to the best of my knowledge isn't explained anywhere. I managed to find the function when I got yet another weapon, a sling, and couldn't aim it further away than a few feet of me. Turns out you also have to hold the left mouse button to "pull back" and be able to shoot further away. Once I had that figured out, I realized what my problem had been with the sharpshot bow.
Two more things about Horizon Zero Dawn: I like the game and would recommend it. And if you start playing, take Silent Strike and Lure Call as your first two skills as soon as you level up the first time. Those help immensely if you like to take down enemies like a silent hunter instead of just rushing in and mashing buttons.