Yeah it's kind of... not great? Lasts for around an hour so there is that.
So it's essentially a generic and as basic as possible summer with sister, you've seen them many times, ends up of course with "i've just been teasing you cause i love you" and all that, the issue with this approach in here is that while you expect it just by definition of this kind of game, narratively (i use this word very generously here) it's not telegraphed at all. Writing wise every single day and every single event will go exactly the same. EXACTLY the same, and not a single opportunity is used to deepen the bond to make the confession earned. Little example: there is a scene where she get soaked after a rain, then come into your room to bang as they do, as she does every day. You could make her catch a cold, have brother care for her and have her saying some uncharacteristically gentle things in her fever. It's a very basic and common way to do it but it's SOMETHING, you know. Instead, i will hammer the point again, every single scene, every singular scene in the game is the same and narrative doesn't move until final event.
CG's look great but holy reuse, there are maybe 5 CG images that are getting reused over and over and over and over and over, and just changing costume doesn't really change the fact. Halfway around you get a new CG and you go all "nice, new content" but then this CG start getting reused as well and you go "oh, i see how it is".
Also at least in my case most of the areas are simply not used? Like at all? Maybe there is something in the endless mode in postgame but i skipped several days and got nothing, but most areas don't even have events in them. So that felt like extra work for nothing.
Overall dissapointingly static experience, both narratively and erotically. Does absolute bare minimum for the game of this kind, it's not a waste of time to experience once but there is very little good here.