It was a bit short, yeah, but the first game was even shorter. This game was also a bit more ambitious by having the whole Nero and Ritsuka duo instead of just one character. I also want to point out that the person who made it isn't an artist. He had to commission all of the art assets. With that in mind I think what he produced was kind of ambitious and probably took a lot of work and the end result is commendable for accomplishing as much as it did for such a niche thing.
As for your general complaints about wanting more from these instead of just bad end simulators, I mean, that would be nice, sure. Thing is though is that there are so few games like this that come out that I'm not sure how you could be sick of them. Stuff like this is so niche that we only seem to get a couple of games like this per year, at best.
We have a game by Ende AA coming out as well this month that's going to blow this one out of the water. I'm sure you already know about it, but I was wondering how interested you were since it's a bad end simulator too, just one with way more content and production value. Also, are there any games from this year that you'd recommend?