Extremely well-made game. It made me realize how many games I'm missing out on in the Japanese adult game market.
Initially, I was turned off from the game because of its primarily pixelated art. However, deciding to finally give the game a shot, I was actually quite surprised!
Despite the pixelated art, the animations of it and the additional sound effects that change depending on factors in the game make up for it. In fact, it allows the game to have a sort of unique charm you won't find anywhere else.
The game is also quite sandboxy in that you can make your own choices on which girls you would like to interact with. There are a few secrets in the game too, though nothing too major. There are sexual events that occur based on meters and points(cg's/scripted scenes), however, there is a sandbox sort of 'sex' mode that allows you to build up these meters and allows you to configure your sexual encounter to however you like. Not to the degree of a simulation-styled game, but you do get to decide on positioning, speed, and where it occurs(for the most part) so that's pretty nice.
I particularly enjoyed the inclusion of the vigilance and 'level of noise' mechanic for many of the sexual encounters. It added a lot to the game's atmosphere and sexual tension and I wish more games had things like this. The whole concept of 'secret sex' is so alluring to me, and I'm happy to see this game actually built on that concept so significantly that they made game mechanics surrounding it.
Overall I was extremely satisfied with my playthrough. The only con I had with the game was the MC being depicted as a shota character. This also played a large role in terms of initially avoiding the game. However, if you are able to look past that, then the game itself is quite good.
I would also have wished there was much more content. This isn't to say the game has a lack of content. Not at all. Its more like, I wish the game had gone on for longer. The game technically ends on in-game day 30. You have the option of going into NG+ to unlock more content, however that is all that is available. It's not bad, I just wished there was more of this game. I really enjoyed it afterall.
There is quite a lot I didn't touch on in regards to the game's mechanics, however, I think it would be best to try the game and see for yourself. You find out what those mechanics are almost immediately, so that should give you an idea of whether you would like to continue your playthrough or not.