SPOILER WARNING: Don't read this comment until you've reached the credits
Just finished it today. As someone who is somewhat into Visual Novels, I can assure you there are quite a bit of VNs that have the same gimmick of DDLC; some of them are even kamige, which I won't name here so as to not spoil them. In fact, both of the major plot twists (the heroine "knows" and cutesy things turning dark) are the main theme of two very famous kamige.
My main problem with DDLC is that the twists are telegraphed waaaay too much. As soon as Monika drops the second "Writing Tip" it becomes clear what's going on. And including the trigger warning at the beginning didn't help either.
That said, I don't want to give the impression that I didn't like it. On the contrary, the big surprise for me was the realization that the game is actually nothing but a huge set-up for whatever Team Salvato is going to release in 2018. I didn't expect all the lore in .chr files. At first I thought it was going to be just a "spooky" ARG, but when you analyze it carefully, you come up with some frightening tidbits of information.
From everything we know the info is hinting at human experimentation, occult symbolism (remember Yuri's books had an eye on the cover, probably the All-Seeing Eye?), clinical torture, sexual abuse, higher states of consciousness, weaponization of psychic powers, manchurian candidates and of course mind control. There are very strong hints to suggest that Monika is some kind of test subject which managed to escape from who-knows-where and is unable to control her powers (like this doc says).
Essentially what I'm saying is that Team Salvato is trolling us: no way they spent two years making just a 4 hours long VN in Ren'Py. This is just one massive set-up for whatever they're gonna unleash in 2018.
RE: Everything is not Doki Doki in the Literature Club