NTR heavy game that I would usually not bother, but if you're only slightly interested in the genre like me, then it may be worth a shot due to the voyeurism mechanic.
I understand those who rate this game with 3 stars, as well as those who rate it with 5. This game does some things really well, while others are a bit lacking. Honestly I'm leaning more towards a 3 stars rating as well, but the older sister named Saki earns a free star all by herself LUL.
Older sister is even hotter than Ryouka (with the kid version of Ryouka coming a close second due to her cuteness) and I wish she got more scenes, but all the ones that she's in (specially the threesome) are the best scenes in the game in my opinion, whereas the scenes with the main girl were hit or miss.
The art and CG overall they are good, but it's a bit of a mixed bag because there are some CG's that are obviously draw in a rush with lower quality and they have weird proportions (for example in the shrine with Oyama 3rd day, their proportions are all weird in the futon).
The main selling point that make NTR fans rate this game 5 stars is the gameplay mechanic where the main girl can be "tracked" via her icon on the map and with cellphone calls. Then you can try and go to where she is and you can voyeur her in different ways. After you understand the system you can see that it is not that complex, but just by existing it is novel at this point in time so props to the developer. I hope that from now on we will see this system copied and improved by other devs.
Another good point is that the maps in this rpgmaker game are small and focused, as opposed to other rpgmaker developers who make huge retarded empty maps for you to move across just to pad out the play time. Here there are even some nice quality of life additions for teleporting back home, a world map for fast travel, advance time, etc. All other RPGmaker developers should take note and stop adding pointless battles system or huge empty maps that just waste time in their games.
But besides that, the game is pretty straight-forward to a fault which is a negative: every route is railroaded and some routes are better than others. This could be down to personal preference of a type of corruption/cheating, but some routes do get more events/CG's/voyeur quality than others.
And you can't even "fight" the cheating or do anything at all, so less of a game at that point and more of a visual novel really, so again the only appeal remains in the voyeur gimmick, where the male MC is just going along for the ride slowly being cucked and impossible to stop it.
When it comes to writing, again, some of the routes got it better than others. Overall its decent, but something more is missing. I wish she resisted more in some of the routes, and some of the scenes in many routes were not that believable for some of the situations or the main girls reactions.
Finally the NTR is avoidable and therefore there is a love route, but as expected it pales in comparison to the other routes unfortunately. There are some wholesome little dates that you can take with the main girl, but that's about it, other than that there are no CGs, no sex, hell not even a kiss on the cheeks with the male MC. The most you get are 4 short scenes of reminiscing about the childhood past with the kid version of Ryouka (cute!), so in the end it is extremely underwhelming, but not unexpected for the genre of game or developers know for exactly this type.
Like I said I could very well rate this a 3, but for the effort of the unique mechanic of voyeurism and the older sister Saki I will give it a 4 star as I did bust a handful of good nuts to the uber slut Saki.