First off, I want to say, I think it's very well done given the constraints of the game jam of dice and dread. Not sure if you have intend to update it, but I'll review it as if it were any other game on the site.
What I like about this game:
(1) The intensity is real. You've created a small claustrophobic space to defend, and it's going to be a long long night.
(2) The lighting effects are great, 2 small dim lights that periodically go out, sometimes leaving you in complete darkness with only the muzzle flash from your weapons really adds to the ambience
(3) Controls are simple enough, and frankly the random weapons add a charm to the game.
(4) The black "zombies" work in your favor adding to that "Oh crap, I can't see, I'm going to die for sure" feeling.
What I think could use some tweaks:
(5) The screen shake gun is too much screen shake. I get it's basically like a regular person firing a machine gun, which winds up uncontrollable if you hold the trigger down. That part is great, but maybe like 50% less shake, or it take 2x as long to get to the extreme point.
(6) Although the lighting works, it's a hair too dim, or at least could use some shifting. I played a total of probably 40 waves before I realized monsters weren't spawning on top of me, they were coming up from behind me and dropping down on my head, and the map has 3 windows, not 2!
(7) Timers on window repairs vs when I can repair them. Often, like really often, i'm standing next to a window, just repaired it and purposely wait to end the wave until I've repaired the window, kill the mob, but the window still loses a point of health. I'm thinking on the time between waves, I should be allowed to repair 1 point of damage on all window, period. So if that 4/4 window was 3/4, it stays 3/4 and I can repair it. If that same window is 2/4, THEN it would permanently lose a point of durability. All windows stay at 1/1 anyway, so it's not a drastic change, and then the player isn't getting frustrated at a last second random durability loss.
What I didn't like
(8) The music... I don't think it matches the ambience of the game after the 2nd or 3rd level. Yes those levels are intense as you're getting a bearing on the map trying to keep up durability, but when the lights go out, that music sort of kills the mood, between that music, gunshots, monster cries, the hyper intense music just doesn't quite fit. To be honest, I tried playing the game with the sound turned off, and when the lights go out and all I can see is the muzzle flash, the game gets much much more intense.
Bugs
(9) If I stand walking in the left side of the map, spamming repair, firing, I get a bug after a couple levels where the monsters just stop attacking me altogether. Since my character doesn't turn black, and I don't feel the need to consume the flesh of the living, I'm calling this a bug.
Missed opportunity to add another level of fear?
(10) So when you first start the game, it's raining, thus implied there's rain, and so near complete darkness outside is implied. I know the windows are boarded up, but it would be neat if there was occasional lighting outside that lit up the entire warehouse for just a fraction of a second. High durability windows would block out most light, thus when zombie spawning is slower there is less/no ambient light except for the hanging warehouse lights, but as the windows get broken and down to 1/1 or 0/1 durability, when lighting strikes, it lights up the whole area around the window. I think this could play on the same idea as the muzzle flash, where the screen lights up for 0.25 seconds revealing a horde and then you're immersed back into complete darkness. Lighting could be random from half a second apart to maybe up to like 30 seconds. Scary right?
(11) boss monster (high HP) every 5 or 10 levels that ignores furniture.
Again great job on meeting the jam criteria, and I'd love to give more stars for more game content :). I'd love to see the already fun game taken to another level.