*WALL OF TEXT WARNING* (There is no TLDR)
I don't know how much Arc pays attention to the comments here anymore, but I might as well give something a try. Keep in mind this will be a logical post based off of what I have found as a member of the AVN community, a few of my own opinions, as well as me using a few of my skills that I have gained by writing uncountable amounts of TDAs during High School (I had a very annoying English teacher and these are now etched into my brain whether I like it or not).
First I would like to make my purpose for writing this clear. This is supposed to bring attention to the graphics in particular as well as hopefully make you, and members of the community (but mostly you), think about a few things.
I've been around the AVN scene for ~4 to 5 years at this point, despite only having an account for about 3 of those years, and I've noticed a few distinct "starts" or "categories" that these game devs tend to fit into. Those categories are as follows:
1. The dev makes a mediocre (to good) game and their skills stagnate for a while. Until they eventually start improving and release an absolute banger or two. I will not be referencing any of these devs by name as I think that'd be at least a little rude to them.
2. The dev makes a mediocre (to good) game but rapidly improves over the course of the game's development. Just about every update showcases a drastic improvement in their techniques, skills, graphics, storytelling, and whatever else. And by their second or third game (if any have been made), or the end of their first game's development, they can usually be considered a master at their work in all, or almost all, aspects.
3. The dev instantly makes a 10/10 game. Right off the bat everything, including the writing, graphics, character design, and sound is top quality. Whether they've had past experience/training or not, is usually unknown. But no matter what, their first game they upload is instantly popular and can be considered one of the best, depending on what the player is looking for.
I can confidently say that you would fit in to the 2nd category. This is because in the 0.2.1 post you referenced how CK's early graphics were "really rough and the programming itself is a mess of spaghetti code and tech debt..." Some of which I got to experience myself. This showcases a rough start as well as growth and development on your part as a developer. You are able to recognize the mistakes you've made in the past as well as make efforts to correct and learn from them. Skills that are invaluable to have.
The graphics (and code) were rough in the beginning because you were new and had only "...two weeks' worth of experience with Ren'Py and Koikatsu..." This is something everyone goes through no matter what it is they're doing. Whether they're actors, writers, painters, comedians, or... Game developers. No matter what, their beginnings will always be rough. Their early works will always be bad and sometimes mediocre. This does not mean that they weren't enjoyable though, as is obvious by your current position and popularity. There are thousands of us here, eagerly awaiting your next move as a result of your early work enrapturing us. Now, your reasoning for the "rework" were exactly as follows in the previous paragraph. Rough graphics, spaghetti code, and tech debt. But things have changed since then. You have grown as a developer and so have the skills and equipment at your disposal.
I do believe the rework/remake was necessary. The scope of the game increased exponentially. Far past what the original foundation could handle, a remake of that foundation was made essential due to this. The story changes are unfortunately unavoidable due to bureaucratic corporate bullshit. However, I believe none of this required the graphics to change so drastically as well.
I sincerely believe there was no need to change from the original Koikatsu graphics that you used. Take a look at the 2nd, 4th, and 5th to last images on this page. All of which are of a substantial quality. You could have remade the beginning in that style and have been perfectly fine. If you still consider the graphics of those images and the later game to be subpar, then allow me to point out a few games that use the same Koikatsu style that you moved away from. These games are, for the sake of this comment, not posted as recommendations and are instead used as evidence/possible sources of inspiration. These games include, but are not limited to, Goddesses' Whim by Ncrow, Crimson High by VertigoAVN, Goth Gasp by FrostMist, and Out of Touch by Story Anon and his team.
Each game I am pointing out for specific reasons. They are as follows:
Goddesses' Whim - I am highlighting this game for the fluidity, expressiveness, and details of the animations; the extra gameplay features, as well as the overall graphics quality. All of which made in Koikatsu with the exact same style you moved away from. As well as using Ren'Py as an engine.
Crimson High - Highlighted for its unique and very detailed facial expressions that the characters have at various points in the game. Pointing out how such a thing is possible without drastically overhauling Koikatsu's graphics.
Goth Gasp - Highlighted specifically for it's unique outfits and character design. A great portion of the outfits were custom made by the dev specifically for his game, using a program I currently do not know about, and imported into Koikatsu. Showcasing how you can use third party applications, such as photoshop to name a common example, in order to create customized assets for Koikatsu to use.
Out of Touch - Highlighted for it's graphical quality, special effects, and attention to detail. It is similar to Goddesses' Whim in this way. Renders made using a heavily modded version of Koikatsu and the devs used Unity to create a sort of "mimic" to Ren'Py. Showcases how far Koikatsu can be pushed and what exactly you can do with it. Despite the models being made in Koikatsu, they all have an incredible amount of detail.
I am pointing out all of these games for my final point in regards to the graphics. You don't necessarily need the noses to make your game stand out in particular. If you are looking for your game to stand out, this can be done in a near infinite amount of ways as I have just demonstrated. And word of mouth travels very far. The shading and lighting of the "nose" style can be applied to the default "no nose" Koikatsu style to a similar effect. Koikatsu itself can also be bent and conformed to various shapes to get it to do whatever you want/need it to do. Third party applications can also aid greatly in improving the overall quality of the game, thus making it stand out even more.
And the final point overall is that you shouldn't forget where you came from and you shouldn't forget who you are. From 2 measly weeks to actual years of experience. You've come a long way from the beginning of your journey and our presence and the discourse here proves it. We were all entertained by your game, so much so, that many of us considered it one of our absolute favorites. That, is why we are so vocal in regards to recent news, especially the AI rumors. I am not one to completely act on accusations alone, but the longer things go unsaid the more I shift towards their side. I already recommended a few things you could do to rectify the rumors and maybe you've already done some of them, as I've yet to check the Discord, and the devlog on the 28th isn't out yet. Anyways, you are someone the AVN community seemingly looks up to, a very stressful and difficult position to be in. And I don't envy you for it. But you should try and stay true to yourself. True to all of the work and effort you've put into the game. And true to your fans.
Hopefully you read this. If you do, then I wish you luck and hope you succeed with whatever it is that you choose to do. Have a great day.