Very nice!
This already feels like it could be a full blown game with it's wave mode alone.
An authentic old-school look and feel, engaging FPS gameplay, nice sound-design and different weapons with animations!
I also see that you had more intentions for the theme which brings me to my main pain point:
You as the player still die as you would in similar games, which labels death very much as an end.
Would love to see what you have in mind and take this further.
It's quite astonishing what you churned out in one week, congratz to you!