Ok. Stop complaining. Here's some alternatives for you to do rather than moan about Technobrake's decisions and creations.
1: Find ANY other Porn/Hentai Game to play, there's so fucking many on F95 and other sites. Maybe after playing other stuff for a year, there'll be new content for NPRI for you to enjoy.
2: Go vote with your wallet, support the dude and comment as you please. He can choose to ignore it or not then. So don't bitch if you don't get a response, he has no duty to you as you don't pay him his bills and economically responsible for his life.
3: You can start making Modded Content for NPRI and implement in it. Learn to code, design and construct content for the game itself, though i'd recommend getting in contact with him to get a clear to implement your Content into his game, so he's clear you're creating content for his project and you're not doing something with ill intent.
I get it you are impatient and hungry for more content. But instead of getting angry at a dude doing this not because he gets paid, but because he WANTS to create this, that he can cancel it whenever he wants to if you keep pressuring the dude as if it's his "Duty" to make NPRI for you hungry, hungry zombies. I suggest putting in some more effort to help him and wish him the best and not attempt to bring him down with negativity. That's not helping him, you or anyone. So drop the entitled dipshit attitude for us all, thank you fucking-kindly-much.