Love it! I used to be a Patron, stopped, and now here I am tempted to re-sub to you!
Still chugging through the school level, but if I had any advice? There should be a better indicator that your magazine is running low. My suggestion is to modify the sound of the shots so their pitch increases ever so slightly once you get to your last 5 shots or so. This is normally apparent in normal projectile guns due to sound of the bullet being forced into the chamber by the spring differs as the spring gets less tension on it (as it has fewer bullets in it), but I've seen this done with energy weapons to great effect in games like Warframe.
It doesn't have to be the pitch, but some audio indicator that your mag is about dry would be an amazing addition.
Also, as much as I appreciate the sounds of moans, you should really look into increasing your library of voices. I'm not sure if it's due to how long I spent playing The Tower or an actual issue of how many there are, but you really start to notice how many are at play after a little while.
Edit: I played it....yeah. I'm throwing money at you again. XD