I give this game a 1/10... I finished it, almost gave up because they reused an entire (very frustrating) level I just did in the next quest... And I can tell you I regret wasting my time on this. The few lines of voice acting and text were not worth this, just use a CG extractor instead...
The story, art, and voice acting is pretty good. I'd give it a good 7/10 or more, going by hentai game standards.
The gameplay... It seemed like an interesting idea on paper, stealthing by enemies etc... But no, it's the most garbage, frustrating, broken gameplay I've seen so far. The stealth mechanic is just bad, even when it doesn't bug out, and the overall movement speed is just painfully slow. It feels like the devs didn't play test their game at all. Riddled with minigames and many minutes of content you have to redo if you fail the sometimes impossible stealth (cause RNG is against you), and constant crashes... Even Cheat Engine won't save you from going mad in this game...