I really like this! The game is great. The interface needs a bit more explaining, and while it might be too much to ask, but I think this game needs to have a map. The first wave of the game is extremely easy to navigate, but once you get to the second, it will get confusing and even frustrating at times. If there was a map, I think that having icons for the ammo and health refill stations would be helpful - I quickly succumbed to zombies because I had no health, but I was unable to heal myself for the inability to actually find the health station.
I like the art style of the game, too.
The game is certainly fun, but there are certainly a few problems.
The zombie spawning might be a little TOO unforgiving. I was almost instantly mobbed by zombies by the second wave - moving around too much in this game is NOT a good idea. You WILL get quickly outnumbered by the zombies, and you WILL die. Not only this, but the amount of spawning places for zombies is unnecessary.
If you let a zombie spawn on you, you can't shoot it - I assume this is because the gun doesn't hit the zombie's hitbox.
The reloading is RIDICULOUSLY long. It's similar to when you look at a clock and it seems like an eternity. This was another contributing factor to a swift death. I will give the benefit of the doubt and assume that this was your intent.
The game has a nice difficulty to it - it actually is reminiscent of Dark Souls, in my opinion. That's a good thing.
The way that you gain points and the cost of items at the stations is ludicrous, and it is both hard to obtain points as well as obtain an adequate enough amount to do what you wish.
There also doesn't seem to be a pause button, so good luck.
As tips, I advise that people don't back into a corner - you will run out of ammo, a wave of zombies will corner you, and once you've reloaded it's already too late. Don't go onto the next wave until you are absolutely ready - as I mentioned there is no pause button as of this moment. Try to memorize the hallways - the game has a low level of brightness so that you only have a limited POV and you don't want to end up on the opposite side of the map with low health and/or ammo.
That said, the game is still above all an amazing game and I applaud you on your great job! Thank you!