All right, played through the whole thing and overall, I think it's a pretty good game; very nice variety in waifus, some depth of content even though the game is very lore heavy: I'm neutral on the story, as the dev havsa certain tone you want to instill on the player and the devs have taken the consideration to adapt it to the players. The dev don't shy away from more serious topics: the orc is one of the better interactions between a colonizer and a slave I've seen in a porngame.
The gameplay though, is odd. The dev seems to want the game to have RPG style systems, including equipment, potions and turn based combat. Well and good, if you were working off of RPGmaker, but this is a renpy game. The visual novel genre does have it's roleplaying games, but these generally didn't adhere to those types because it's asking it to do something that it isn't made to do.
As someone else mentioned earlier, there is a very strange lack of progression; combat, after the prologue, is mostly about figuring out when to use potions. Having your health always go to full between combats means they lack pressure, but in a way it is good that every combat encounter is designed with simplicity in mind; far too many devs seem to think that they can somehow combine a complex videogame and a pornogame and have both parts come out great: this isn't really possible for small, often solo devs to do in any real way and even if they do manage it, they spend time and resources on it that might have been spent streamlining UIs, writing more smut or just living a human life. (this is allowed, ya know)
If you're going in the direction of adding equipment, or levels or such, reconsider into having these system be simple and tie into the actual gameplay, which is bedding waifus and breeding them. Remember things like the mining minigame in ME2, which infamously turns an action rpg into a bad game of hot and cold. Ultimately, you have to try and remember that what you want is to tie as many systems well together into the core: instead of buying random equipment and having many types, you can instead tie them into gaining favour with the love interests: this means that players are rewarded and encouraged into things they want to do anyway.
Alternatively, seeing as Spawn is very obviously an influence on the game, you might have the character and the parasite gain strength from fucking and to a lesser degree killing. You already have a good system for that, with infection, but changing into from a purely negative system into one with give and take is narratively and game-systematically satisfying for a player. It doesn't have to be much: small additions to energy, health and maybe damage as major milestones would still meaningfully impact the game. You could instead have equipment grant abilities: this would also mean that making fewer, more unique pieces of equipment would work out.
Obviously, you probably have your own ideas and systems that you are already working on and will probably implement. It's easy being an ideas guy so take all of this with a grain of salt coming from someone who is really just an anonymous stranger.
The love interests are set up fairly nicely and feel like individual characters. The dev, or the artist or both, have the type of "big muscles, big tits" and I applaud their taste, but there's always the question of maybe, possibly, there existing other body types. Petite, a bit chubby, what have you. The childhood friend comes sort of close but she strangely just disappears after her scene in the tavern; I take it this is more a remnant of the game being in early stages yet, same as the, odd, inclusion of corruption which as far as I can tell doesn't do anything.
As for the UI, it suffices. The game map has quest updates but in general, progression is vague but it seems that is a work in progress that is progressing. Overall, a fine piece of fiction with plenty of promise.