The description should really be "...as you traverse the mysteries of the universe and the nefarious plots of the USF, and fuck absolutely everything." That would create more accurate expectations of the game's sexual decisions.
Before the creepy scene in Noel's manor, I'd probably be giving this 3 stars. I'll probably continue this game in the future; it's not irredeemable, but I have to knock off a couple stars for ethical reasons. The biggest is the lack of consistent consent. The worst is the scene with Nyx and the prisoner - that's just straight up sexual assault. The scenes in Noel's manor aren't much better. It seems like the servants are just sex slaves, which makes everything that happens extremely unethical; slaves cannot give consent. Maybe they're free people forced into servitude due to their poverty, but then, as their employer, Noel still can't be making sexual requests of them. I can't think of a way that anything in those scenes is ethical. (Don't think you can avoid the problem by silently invoking "alien culture." If they have different standards of consent, that needs to be actively mentioned.) A few of the sex scenes with the main girls should have clearer consent too.
The other big problem is the breast size. Nearly all the boobs range from "very large" to "ridiculously large", and I prefer a slightly more natural range. That wouldn't be a problem if it was recognized as unrealistic. Instead, the writing gives the impression that DD breasts are the norm, not the sexy exception; what the fuck is Lym doing feeling insecure about her breast size? And don't call Sybil's breasts "tiny" when they're at most a little below average. When you perpetuate the idea that only enourmous breasts are normal, you're doing everyone a disservice. It matters; why do you think that like 80% of female pornstars end up getting boobjobs? Because they've been given a distorted idea of "normal".
With ethics out of the way, here's the rest of my review. Do note that I really struggle to write positive stuff, but this game does have positives. Without the previous complaints, I'd be giving this game 3 or even 4 stars:
the good: the writing is mostly decent, the girls have actual personalities, and the overall plot is interesting enough. The sex scene animation is decent, and I like that it's in first person.
The bad (because I'm much better at complaining than praising):
Some of the sex scene writing is poor. Don't use euphemisms like "love-cave", it's weird and not nearly as sexy as more direct words.
Also, why is there no actual scene when "the shuttle to gregoria prime quickly transforms into a hot, steamy, flying fuckpod"? That's unprofessional.
There should be more options to not have sex. Not everyone wants to seduce everyone around them while secretly plotting to incorporate them into a harem. With Noel and Dr. Clermont, it seems like it's just sex at first, so that's ok. But with Lym and Sybil, the MC acts like he's starting a relationship with them while they're naked, and then just ignores it all the next day. I'm not opposed to harems, but I feel like the MC is making false promises and therefore being an asshole.
The almost complete lack of choice is a problem. Some stories can be told without choices, but given all the strange stuff and complex relationships in this one, I think it really needs choice. I don't just mean sexual choice, but also more choice in things like whether you tell Lym that her sister is doing secret important stuff, and that she told you not to trust the Admiral.
The gallery is incomplete. I feel like it's missing scenes, and one with Dr. Clermont is repeated twice
Let us skip wierd giant scaly dick alien sex scene. That is sooooo not my fetish, and I'm sure I'm not alone.
You don't need to describe every woman as "beautiful". Just let us look and decide.
Dr. Clermont should have left the basic vitals unaltered. They're going to notice if heartrate doesn't correlate to missions. And Dr. Clermont's rationale for deactivating the tracker should be a little better explained. The way she says it, it doesn't make her seem trustworthy at all. She could say something like "They aren't just to monitor your health, they're to determine how to hurt you. I took an oath to do no harm, and it's clear that that's what these trackers are for."
If you're going to use magical interspecies stuff where aliens can get impregnated by humans, don't invoke science/reality by talking about DNA. Not ever. Keep it just space magic.
Similarly, The drone description of the protectorate is, at best, silly. Don't get into the details of technology if it's just space magic.