At this point it is likeliest I make a game with the same setting and characters in a totally different genre, I kind of bit off more than I could chew with this, haha
Honestly, that's fair. Still, I'm a sucker for alien bug RTSes.
For that gameplay feedback I promised... first, a few bugs I noticed: You can start the process of gestating a new unit the moment the "gestation" meter for the old one disappears, meaning you can start making a new unit while you're actively in the process of birthing the last one. Also, if you're shooting with a wall above you, the bullet hits the wall the moment you fire it.
I think the gameplay of this controls pretty well, although a shortcut for something like "select all of X type of spawn" or even just "select all spawn" would be nice for ease of commanding. As it is, it's a bit annoying to try and select all my units at once. Also, I think an option to zoom out the camera would be nice, so you can command units to go into rooms ahead of you more easily.
As you mentioned, the balance in what you have here isn't the most difficult. There's nothing pushing you to not just spam out a bunch of spawns, and honestly, using spawn in the first place seems a bit unnecessary, you could probably do things fine without them. A lot of the game is running between rooms of enemies, so there's not a lot of time where you're not going to be hindered by the movement-speed decrease and eventual total immobility from hatching new units, so it sorta disincentivizes you from actually engaging in that mechanic. Something like having a second "front" to defend from encroaching enemies while you attacked on the first would give a very good reason to need them.
I feel like you did well with the visuals of the game, the enemy destruction effects were quite satisfying, the environments look nice, and the birthing menu UI was very nice to look at (even if you're not in that menu for very long most of the time). And I have no problem with the movement. The command buttons were a bit unintuitive, I often found myself trying to leftclick where I wanted units to go rather than rightclicking, but if the game was longer, I probably would have gotten used to them.
Hope this feedback helps, even if you don't continue this game.
Edit: In the last level, I noticed that the 2nd unit type was a bit finicky with when and who it would attack after an attack command was given. It seemed kinda like once they killed one unit, they'd get stuck and not attack other units. Also, when I had a lot (like, 8-10 or something like that) of units, the game crashed when I gave all of them an attack order, then switched them back to defense to cancel it, probably something to do with too many commands going at once for the pathfinding system.