I am really shocked at how nobody in the comments has the courage to tell you how awful this game feels.
I think it's because nobody wants to have their game hate-rated in return, however I'd rather have my game hate-rated but give you some actual useful feedback than gaslight you into thinking your game was great when (in my opinion) it has a lot of issues...
The game design feels very flawed, I think having friendly fire on the king would have added some much needed creativity, but as it stands this is just a wave-based shooter game and that's about it. The choice of weapons (manual / auto) gives you the choice between 2 weapons that do the exact same amount of damage, except that one gives you the comfort of not having to click every time with the drawback of hurting your ears while you use it...
The purple slime being exactly the same as the green one with just more health feels like a wasted opportunity to make the game more interesting! I could've totally seen some enemies with different moving patterns or maybe the ability to shoot you!
There's no bonuses or perks that make the game more interesting, every wave just feels like it's the same loop over and over again where you move around the king and shoot the enemies.
As for the sound design, the music is fitting enough but the gunshots really hurt to listen to, especially the automatic one. It's also lacking a lot more sounds that would've added some depth to the game (new wave sound, monster sound, etc).
The screenshake is something people often turn off in games, I think this should've been considered during production if you really wanted to add it in.
Every designer might have a different opinion on this, for me the friendly fire on the king would've made this game a lot more interesting, that aside you should consider adding some variety to the game (perks, bonuses, new weapons) and most importantly look into having the gun shots be more satisfying than just using the same overlapping sound over and over again (using a random pitch already works, maybe using an uzi sound and making it a bit less raw would make it sound nice too!).
I appreciate jams because people get to watch what you made and comment on how they felt about it but I think for this game particularly, people don't go out of their way and just say the game feels nice or fun when I can already see them rating your game a 2 or 3 out of five at best...
I hope that moving forward people will be a bit more honest, because we're here to learn, not to pretend we like something to get more points!