what is this and why?

Finally here , I've been waiting this for a very long time and it's probably going to be my favorite . So please be creative making those backgrounds and emoticons. I appreciate everything you do guys keep it going My Muv-Luv Fans Post for collectors : https://steamcommunity.com/app/449830/discussions/0/1651043958630842634/...

The Steam page doesn't specify nothing but a recently interview explains it: It indicates that it’s been ported to the Ages Mark 2 Engine, which is the same engine we used for The Day After. It has a number of advantages because it’s much more modern and much easier to maintain. The big goal with the new engine is that we can ensure that the game will still be able to run for the next 20 years, because the old one was kind of long in the tooth. Interview link: https://twinfinit...

since like all these games based on hentai franchises

Is there a chronological order or anything to play the VN? and is this some sort of epilogue or an entirely new spin-off? Thanks.