This review is for v0.8.0.2
TLDR: 90% text, 5% banging your head against the wall, 5% actual porn, and way too long and vague to get to anything good.
So I'm going to start this off by pointing out that I played this for several hours straight before leaving this review (maybe 6 hours) and in that time all I did was repeatedly click on the available locations as I tried to aimlessly figure out what to do to progress the story.
Fun fact: you literally can't progress the story manually, you have to wait for time to pass by until the game itself decides to progress the game on its own, meaning all you can really do is bang your head against the wall trying to find hidden scenes in quests until the game decides that you get to progress to the point that you actually get to progress quests.
So gameplay gets a solid 0/5
Then there's the fact that "veteran detective mode" is repeatedly thrown in your face, but the only way to get access to the code that unlocks this mode that severely reduces the amount of stupidity in the gameplay is by forking over actual money.
Considering nothing in this game is unique outside of the plot (which has honestly been done to death in smut), that would just be a waste of money as you could get the exact same plot by looking up any kind of nun porn.
The biggest issue with this game is definitely how much it wants to waste your time, which is why there are so many posts in the comment section just looking for the full saves, because actually playing through the game is an absolute slog.
I really don't know why this game is rated so highly by so many people when it is mediocre at best, with the best thing about it being that the English is actually legible and it actually does reference legit things that actually exist, so the creator clearly has done their research, and even did a good job of putting the classic Christian closed mindedness, gullibility, and "love for others" into play for multiple of the characters interactions, which really made it feel immersive. The only problem is that there is waaaaay too much text for a porn game about horny nuns.
So the writing is good, there is just way too much of it, which gets it a 4/5
The next thing of note is the porn itself, you know, the main reason we're all here.
It is spread very far apart, with a very slow build up that suddenly jackhammers you straight to blowjobs and fucking married women, then plateaus for way too long with your character no longer gaining additional corruption purely because otherwise you would progress in the "plot" faster than the plot itself wants to keep up with.
Combine this with the fact that the porn you do get is all very vanilla for the first 6 hours of gameplay and you're going to be more focused on banging your head against the wall trying to progress the intentionally slow story than jacking off.
So the porn gets a 1/5
Overall, this feels like a writer wanted to write a story about a "demon" haunting a monastary and needed Constantine to come investigate it, but realized that they needed something else to draw people in since that story has been done to death for hundreds of years, so now we get a very long visual novel with lots of extra steps and very little porn.