200IQ analysis. I felt quite the same. He's taken a very experimental route in this game and I believe he spent more time cultivating the environment and system than the scenes itself. In the previous game, you were the female protag and your actions result in the corruption, therefore it was quite linear. Whereas in this, the female character is the main character, but you are not her. There's a lot more to develop in the system in order for an NPC (the female main character) to make the world believable to you, the player. You are an observer in a world, not the player who creates and manipulates the world to his will (apart from the initial trigger events). He probably struggled to balance the environment vs the scenes and is probably the reason why the scenes are a lot less than tina (Compare the recollection room sizes). I'm not sure but I think the length of the scenes are shorter as well.
I actually wonder how much he's researched to come up with a system and story like this, or is it just a result of him consuming various amounts of erotica and hentai related stuff. Not trying to be pretentious in any way, but I do feel there's some depth to the system he's created (The sales figures on dlsite prove my point).
Will there be an upcoming dlc? I most definitely think so. The way these guys work is, they leave some plot holes open on purpose and take a rain check and see if the game gets good traction and demand. If so, they begin working on the dlc.