The visuals are alright. My biggest issue with them was that there was a lot of z-fighting on the walls and the game didn't have any v-sync options, so there was a lot of distracting screen-tearing while I played.
The atmosphere could use some work. I think more ambient audio would have helped a lot, and maybe a vignette effect appearing would make the monsters more imposing. Speaking of which, I never got caught by the monsters since they moved pretty slowly and you can just walk right past them. A lot of the tension and fear dissipates as a result. All that aside, I appreciate you not using jump scares, since they're kind of a cheap and easy way to make a game scary.
All that isn't to say I disliked the game, though. I loved the story! The "twist" near the end when you realize you're on a plane and you had to collect the oxygen mask to put on the bust had a huge emotional impact, and leaves a lot to be interpreted. The cool colors of the corridors contrasting with the red eyes and lighting of the monsters is really neat. I think the pictures on the walls helped with navigating the maze, but I think there could have been more of them.