I managed to play it in full screen at 1440p through the part where you get the Eyeshine ability, and end up in the showers. At which point the game hung in the middle of loading the level.

Ever since then when I start the game, the whole picture is horizontally squished with black above and below (maybe due to pixel ratio being off somehow)? I go to the video options and my 1440p resolution is already selected. But if "full screen" is on and I hit apply, nothing changes. And when I leave the options to go to the main menu the game just hangs.

If I set full screen to off, I can even use my 2560*1440 res, but the taskbar appears below, which is annoying but at least I can play.