Honestly it's pretty damn good. It's obviously a copy of the anime solo leveling, and since season 2 just ended this fills a nice void. For whats good: if you like solo leveling the anime or anime similar to it, you'll like this. It's basically the same thing, portals open, people get awakened powers, they go in and kill monsters to seal the portal. The girls and the graphics all look great, and they really improve the further you get. The MC is likeable without being cringe so thats also nice. I've seen that people are bitching hard about the english, but to be honest it's really not even that bad. Yeah there's some awkward english sometimes but unless you were dropped on your head as a child, you really should not be getting confused by it. I've seen PLENTY of games on here that are highly rated with far worse English than this, so there is no problem here besides some awkward grammar. I saw no typos at all, which is very impressive when you learn the dev says English is not even his second language. The only other negative thing that I really think I could say is that some of the sex happens too quick, it's literally just hey let's have sex, ok sure. On the other hand... do you really want to have 7 chapters of nothing happening before it gets good? Honestly overall I think it's a damn good game with only very minor flaws that will undoubtedly get ironed out over time.
TL;DR if you're a fan of the anime solo leveling, you'll love this. If not, you'll still also love this if you love urban fantasy/fantasy games.