TLDR: No gameplay, no story/plot and only OK pictures.
There is almost nothing to this "game".
You do the exact same activities every day.
You have two activities to reduce the uncles suspicion that are very simplistic minigames and a maximum of six activities with the aunt, of which you can realistically do four if you want to reduce the uncles suspicion twice every day.
After some time you can slightly progress with the aunt activities, for example: Hug her while watching TV instead of just sitting next to her. Or Jerk off to her sleeping instead of just watching her.
Activities you can't really do with her is to help her in the kitchen or do something with her at the washing machine in the bathroom (never even tried that) because you have to do the activities with the uncle to keep the suspicion low enough.
Question: Why does helping her in the kitchen raise suspicion? Why does enjoying the sun next to both uncle and aunt raise it? Why does watching TV next to her, but with both of them raise it?
This one loop is all there is to this game, I guess with the kitchen and washing machine being the activities you only ever do when you have progressed enough with her and suspicion is low enough that you can do them for a change...
Only positive is that aunt pictures are mostly good (though I don't find her nipples that good in the "Bathing together" scene and her bikini-zone is censored...
Two stars is generous, but I feel that this is not terrible enough to get only one star (actual rating maybe 1.75 stars).