Review
You've successfully made an FPS in the style of the old 2.5D classics like Doom. The mazes of enemies, gunplay, and whatnot are all here. The bad news? You've successfully made an FPS in the style of the old 2.5D classics. Unfortunately, this means that the aiming is not perfect. I think that the character should start turning slowly once the player moves the mouse to the edge of the screen and turn more quickly when the mouse is closer to the edge. The current setup is not bad, but is not ideal. Furthermore, I know this is what the game was going for, but I find the dirty brown corridors ugly. It works perfectly fine, but don't expect any awards for graphical excellence. Don't mind what I just wrote too much though.