Glad you liked it. A lot of the filesize does come from the audio, but most of it comes from images. Since the girls facial expressions change pretty frequently, it adds up. In this case, they're not just an image of a facial expression, they're whole renders. Mostly because when I first started making the game, I hadn't really considered filesize becoming an issue, and to fix it now would mean cutting faces out of literally thousands of renders. It would take weeks lol. Animations are another thing that takes up a bunch of space, but there's no way around that really without dropping the quality. Depending on how you played it, it's possible there's a bunch of animations you didn't see. I figure I'll just have to seperate releases into chapters or something in future instead of just having one massive game, because otherwise by the time this thing is finished, it's gonna be like 50GB.
If you already kinda figured all that then one other reason the game might seem sort for the filesize is the branching. Unless you went back and played the game multiple ways, there are whole scenes you won't have seen. I don't mean just gallery scenes either. I won't go into detail here but yeah, that's another thing which increases the size. It really is intended for multiple playthroughs, but not yet. I'm developing it with what it will be when it's done, rather than what it will be when the next version is done. I get pretty mixed feedback on that fact, but that's ok.
It was originally planned to be a sandbox once they got to the academy, but I scrapped the idea because I didn't want the scope to run away from my capabilities. I figured it was safer for the longevity of the project for me to make it a standard VN. I did still want to include sandbox aspects though, which is why the ghost hunt is the way it is. There's another one planned which I'm hoping to be a larger, more in depth version of the first one. (As in, same concept, but new location and story, with new stuff like more events, a ghost that actually moves, etc)
It was super fun to make, but I think I'd get burned out pretty quick if I tried making a whole sandbox game, rather than just a section.
The outfits are there mostly as just a dumb collectable, and don't currently do anything. They were originally supposed to give you a way to pick your favourites of each category, and it would increase the chance that a character would wear that outfit in the main game, but this was back during the sandbox plan, and has since been scrapped. I'd love to do it still, but the amount of work it would take, vs how much it would actually matter, just isn't worth it. Also, I'm aware of the double notification thing, if you're referring to when you load a save and the notification goes nuts. It's definitely a bug, but I'm not sure why it happens, and haven't yet put the time into working it out, since it's very minor. If you're talking about multiple notifications at once, if they're for the same outfit then yes that's a bug (Though not one I'm aware of). If they're for different outfits, there are a few points in the game where you unlock multiple outifts at the same time, and so it could just be that.
The scene that my PC died on is a strange one. There's nothing particularly special about it, it's just a conversation between Kellin, Akemi, Olivia and Taliya that takes place in the dorm common room. No clue why my PC seems to dislike that scene specifically, but my GPU is a 7 year old 980ti which has seen almost daily use for those 7 years, so I'm surprised it still works. I figure since it's not that important of a scene, I'll just fix it when I can, and people can make do with my incredible MS paint skills for now. It wasn't worth delaying the 0.21 release over imo.
Glad you like the translation effect. Foreign languages (Well, foreign to me) are something I wanted to try to do in a somewhat specific way. I wanted to simulate the fact that MC doesn't speak these languages, by banking on the fact that the player most likely doesn't either. Or at least not both of them. As such, I don't provide translations most of the time. If what's said is something important enough that MC should know, he'll just ask the girl to tell him what they meant. (Just as you might if you had a partner who's native language you didn't speak.)
However, because it's implied that MC would be hearing the words they're saying, he would at least hear the sounds the words make, which is why I provide the romanization for the words as well, since most people who don't speak Russian or Japanese aren't gonna know what all the cyrillic or kana characters sound like. Silly detail really, but I like silly little details.
The exception to this is when it's important that the player knows what's being said, and either isn't present, or it's an entire conversation which isn't practical to have a character translate to MC, such as with the Akemi/Hikari talk scene. (There's 4 different versions of that scene btw, depending on what happened to Hikari :D) For scenes like that, the translation effect is used to imply the conversation is taking place in a language other than English. (One guy thought it was an MTL bug lmao)
I really didn't wanna just put "*In Japanese*" at the start of each sentence. I'm British, and I don't speak either language myself, though bits and pieces of both.
I'll most likely be using the translation effect for Sasha later on as well, because I have plans for her which will necessitate full Russian conversation. Sasha's overall story is probably my favourite out of the girls, even though Riley is best girl.