It is and I wholeheartedly suggest trying it out. Without going into details specific to this game, this is what is called a Denpa game, I'll just quote from VNDB on this as I am not always the best at putting things correctly, not dyslexic or anything like that, I just don't always have the easiest time getting the point across.
There is one event in the 'happy' scenes category, that's the category where the horror tag comes from for this game, that does seem to spook some people, but most of it is just weird, not actually scary. There are also some things that happen without a choice where even the MC doesn't seem to be in control. You'll know them when you see them as it gets acknowledged in the text.
Also keep in mind that, while VNDB doesn't say it, Denpa is known for not having a very happy tone to it. Most routes will end in some level of sadness or other negative emotions and there is likely to be no truly happy ending at all or, if there is, only one that will come as the final route to be developed.
As for a game for 'just fapping,' no, this is not that kind of game. There is going to be very little in the way of sexy time with any of the characters and it will be slow burn for some of them. When each girl becomes open and ready for sex is entirely dependent on the kind of person they are. The ones with stronger moral views on sex or who are introverted and quiet are likely to take a long time to get there while the rest are likely to take less time. This game is entirely story driven in this aspect. The girl has to say she's ready and offer herself to the MC before the sexy times will start, that is, unless Selebus is willing to add rape, which I'm not so sure he is given he had multiple chances already.
Also, 'just fapping' is actually likely to get you stuck. In this game, you really should pay attention to every single detail as some of it will come up later in ways that will get you stuck.
Also, it is recommended NOT to try for a single girl, those routes aren't in the game yet and that will only get you stuck by not having a girl you weren't going after leveled enough for required events to trigger. It is recommended that you grind them all as equally as possible on this route.
It is going to be a while yet before single girl routes are even started, this is one of the general routes, the 'dark' route, which will likely have the most negative of the possible endings.
.. hmm should i say we are all dead then ? ... i didn't plan on being spiked to a freakin cross dammit 
