Alright, so I'm not sure if you've gotten a lot of feedback on this outside of here, so this may or may not be outdated by the time you read this.
I'm gonna start with the primary things I think you can logically work on, and leave my large personal complaint to the end.
First of all please consider allowing the mouse wheel to perpetually scroll through the weapon wheel and/or allow the player to select weapons with the number keys.
Second of all, the player moves way too slowly. Increasing the movement speed outside of combat, or adding a sprint button would help a lot.
I am not a fan of the universal ammo pool, nor the current ammo restoration method (though it was much more functional/intuitive during the boss fight). For one thing, every weapon that isn't the rifle drains the pool way too quickly and doesn't do enough damage to justify using, doubly so for the alt-fires. This makes every gun besides the rifle useless.
The wave system is also not very well defined, and it's very unclear as to what enemies need to be killed in order to progress. The problem is most severe on the second, pre-boss mission.
Here's my very quick opinions on the weapons in the game
Rifle: Honestly pretty fun to use, but mainly because the shared ammo pool does not work well with the other choices.
Alt Fire: Eh. Sniper shot is one of the most boring alt fire options for a rifle.
Flamethrower: Feels terrible, but I don't blame you for this. Video games can almost never get them right.
Alt: A shotgun fan blast? Not very interesting, nor useful.
Grenade launcher: Honestly hated it. The grenades slide way too far and too fast, and the lack of a proxy fuse is painful, not to mention how fast it drains your ammo.
Alt: Actually kinda cool. It's tough to design Grenade Launcher alt-fires. This one's not a bad take. Still don't like it.
Please consider giving NPCs dismissal dialogue once you've talked to them and they no longer have anything new to say. Examples follow:
NPC gives quest, you talk to them before you've completed it: "what are you waiting for? go get me my void ember!"
NPC has no more current information/scenes: "You again? Get out of here!"
Probably an early game issue more than anything.
Okay, so my personal complaint is the PC being an anthro male, definitely not a fan of that. In fact, I had a huge copium going in that "m-maybe he magically turns into a human when he lands?" because of the H-screenshot, but noope. I guess Dirk just shaves his entirely lower body and dick? Interesting to see a protagonist into manscaping!
Joking aside, I'm assuming that the reason Dirk's lower half is human in that screenshot is because it's a placeholder. If it's some attempt at a half-measure in the vain of "oh don't worry, he's human in the H-scenes!" I would actually advise against that because that's literally going to please no one.
Obviously there's probably writing/lore, or maybe marketing reasons Dirk is a rat, but if a human option, as in actually a full sprite and not just for the H-scenes was added I'd be be happy with that, at least enough to somewhat follow it. But that's entirely up to you, and I'd be accepting of any reason you have for the MC being what he is and not trying to appease weirdos like me who want a human MC.
Anyway, even aside from the MC issue, I think the gameplay has a lot that needs to be worked on, but it is just a first step.
Reading back I was a bit vague on some of the combat issues. If you need I can give a much more in-depth breakdown of why I don't like the current combat/wave system, but since you mentioned a June update I wasn't sure how much off-site feedback you had already gotten on it and whether a breakdown would be a waste.