On the surface, it's a Mystery-Adventure Harem AVN that looks like a parody to 'Ready Player One' or just about any story where playing and progressing through a VRMMO is a major focus.
Dive a little deep, and it's actually an AVN that hearkens back to the kind of storytelling that you usually see in Old School Eroges where the character building, worldbuilding, and a plot that does not completely center around banging women are given more focus (which makes it stand out a bit from the rest of the competition that feels like they have a same-y premise). The plot certainly isn't original, but it's good enough for people to be invested in it.
It also happens to be the dev's second game, where he fundamentally improves upon every aspect that the first game was sorely lacking (i.e. better music, a somewhat more focused narrative, better development amongst the LIs, better cinematography, etc). Speaking of the dev, he is also loved for having a somewhat speedier release schedule which he sticks to for the most part, which is a breath of fresh air in a scene that is notorious for having devs that have very drawn out release schedules and a high attrition rate.
Of course, it's not without faults. Branching paths don't fully exist in this game (which is prevalent in some eroges where there is only one correct choice and the rest lead to losing an LIs path or a bad end), though on a positive side that allows the dev to just hammer through updates without having to worry about making completely unique paths depending on player choices (which leads to longer dev time). The humor can be a hit or miss, probably more so than the first game where the humor there feels like it's dialed up to 11 (whereas the humor here sometimes doesn't hit well due to the more serious nature/tone of the story). And the visual style can be a turn-off to some people who may not like the somewhat "JRPG-ish"/"Anime-ish" style.
Still, overall, people like it because it's a fun ride and has aspects that a lot of people find endearing - whether it be the characters, the humor, the music, the plot which encourages them to theorize what will happen next. That's pretty much it.
*This post was brought to you by the Church of Nova.
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