This game has a lot of refinement and visual appeal. It also has a very good "look and feel" to it and presents itself as a well-rounded, solid project.
If I were to suggest any improvements, it would be to include more songs which could fade in and out depending on the current zone that the player is in. Also, adding robot sounds and shooting sounds would greatly enhance the experience. I would also suggest a "run" modifier key, such as <shift>. Finally, user-defined keymapping would be a welcome addition (I personally found it awkward to use the <E> key to interact with objects, especially doors, when I am so accustomed to using the <spacebar> key instead from past similar genre games).
I really like the unlimited ammunition of the firearm. And the robots look really neat too. I like the creepy, tense atmosphere of the maze, and how the field of view is limited shrouded by distant darkness, making each corner turn more intense as you progress through the maze.
A really impressive project overall. I don't have much of anything negative to say about it. Really nice "polish" and refinement. More levels or missions please!