I think it was cool and definitely worth finishing. I'm glad I knew it had a twist, and I think the game is designed in that way. Especially with the warning that first pops up in the game, and the overly silly presentation. It drags quite a bit in the first arc, so knowing there's a payoff is really important.
That's one of the best things the game does I think. You know going in there's a twist, but the first arc is justttttt long enough that you get legitimately bored, and wonder if you were bamboozled in the first place. That it really is just a dumb little VN. It's a brilliant way to bring your guard down knowing that in the world of the internet, you will have been spoiled at least a little about the twist. This effect happened perfectly for me, right during the baking date with Natsuki. Of course, the next scene is where shit goes down.
Another good execution is how they handled the scene where reveal Sayori's suicide. It was very obvious and predictable that it would happen, ever since the "I love you" scene or even before. But they coupled the emotional in-game character twist with a very surprising 4th-wall gameplay twist and a total shift in tone, which made the predictability of the suicide irrelevant. I had to turn the lights on in my room because it made me legit uncomfortable, which a plain suicide scene would not have.
Overall I wish there was more puzzles and weird glitchy things to play with throughout the rest of the game. Playing with the chr files was really cool and I wanted more of that instead of just more creepypasta. I especially wish they focused more on the characters and gave them a good payoff in the end, instead of just being vehicles for Monika's manipulation. Sayori ends up being the only actually good character because of that (which sucks cuz #TeamNatsuki), and it makes the 2nd arc feel half baked.
Monika was cool. She's an allegory for the illusion of total control that an artist has over their creations due to the need for an audience/player to actually interact with the art and give it a meaning which the artist cannot control. But there was not much else to her character beyond that, so it's hard to be emotionally attached. Again, it leaves Just Sayori as a good character. ---