It's a short (short for a japanese VN) and sweet incest game full of love. It is mostly text based (not too many CGs at all) but it's fully voiced
The mother is the classic sweet and loving mother who is willing to have fun with his son. The sister is the classic shy as fuck young sister in love of her oni-chan and it's jealous that he is always looking to his mother.
The game is very sweet and vanilla (I won't recommend it if you are looking for anything hardcore) full of love and care. The dad is there and you are cheating on him but in my book that's just the A in the ABC of incest so this game is vanilla as fuck.
The game is short (maybe less than 5 hours). You can only "choose" 6 scenes from a total of 10 scenes (I may be wrong, it's been a while since I played it) with 2 "routes" (mother and sister) and 2 ending (happy ending and happy pregnant ending).
The CGs are good in quality but bad in quantity, I remember something like 2 CGs for each sex scene, so maybe you will face a huuuge text of wall looking at the same CG, but the game is fully voiced so that wall text isn't tedious at all.
IMO I really loved it. I would like to find more games like this one.
TLDR: Great and sweet game full of love, not too many CGs but the game is fully voiced. Short but good. Definitely worth playing. 4/5