Thanks for the reply! I think you're right about the issue being drivers or Big Picture mode, I'm a bit scared to change anything in Steam since I finally got the DS4 working for Final Fantasy 15 with the correct button prompts. I remembered I had a wired Xbox One controller for the Steam Link in another room so plugged that in and after configuring the controls it worked fine. So much better playing with a controller, maybe I'll even beat the second boss! I love the feeling of having to move into danger to restore your health, it gives it such a unique feel compared to other shooters. I find myself trying to barrel roll back in the opposite direction too soon which is currently the main thing getting me killed.