1 year and they managed a solid game, one of the most sold games on steam, not "finished" if you're going to be nit picky about some parts of it like the infirmary or some levels not having mini games or extra content, as I've said, the game's been cooked for a while and got endings, lots of kinks and a fully developed corruption system which is the main CORE of the game... What do you want, a properly made game that the dev can call "finished" in 1 year, or a Ren'py/HTML game with more than 3 years still not finished...? Personally, I prefer the first option, and let me remind you he made all of this on RPGM, it oozes originality like no other game on RPGM, but if you know a game better than this one, then be my guest and share it with all of us...
Proper english reading is something that a lot of games don't have, if we're talking about H games, and good ones, not many have it, you seem to forget almost the majority of games that have been released have come with MTL, good luck understanding plot, skills, items, proper usage of things and objectives with it, unless you're using Mtool or other translators it can be extremely tricky to play some games...
I don't know about your examples since, personally speaking I am just an enjoyer of Remtairy games and don't care much about everyone's opinion, but seeing so many people complain or want X or B extra thing on a game that most here didn't pay for, it's ridiculous, one thing is suggesting something, the other literally complain or demand something, and I've seen that from time to time checking this thread, I get it, half baked fetishes are annoying, but can people, just at least a bit, be able to appreciate what they have...? Guess not...
I'm calling it a 10/10 game because, if you compare it with other H games... Do they manage the amount of openly spread content, amount of fetishes, a VA's that makes the majority if not all of the conversations voiced, proper Turn Based Combat, core mechanic properly executed and implemented (the corruption of the female protagonist and descent into a slut)...
How are the majority of corruption H games...? oh yeah, girl starts disliking it, is completely submissive and then with little or almost not many scenes or time she's turned into a slut with 2 scenes at max where she enjoys it and at best 3 new dialogs with 1 or 2 face CG's swapped. Oh and I forgot to mention, it all happens because either she's getting hypnotized magically into it, or a devil tricking her into it, or a magical fantasy that completely corrupts her to the core with almost no prior or in between balance...
Obviously I call it a 10/10 game based off my own assumption from my time playing adult games, if for you a game that offers as much content as this one, isn't a solid one (which I know isn't the case, you've enjoyed it but are hungry for more), then mate, I don't know what to tell you but a game that comes to get this one out of the throne as one of the, if not, the best corruption game, won't happen in at least 2 - 5 years at max... (I really hope in less time but it'd be impossible)...