You might like my game - Hentai Possess-Her by GreatherGames (itch.io) - art style / chest size maybe? (sorry for self promote)
I would also recommend - Our Apartment by Momoiro Software, MiNT, Sacb0y (itch.io) - a lot of custom options and possibly - <a href="<a href=" https:="" juicyeliot.itch.io="" juicy-futa-current-build"="">https://juicyeliot.itch.io/juicy-futa-current-build</a> with a variety of characters.
Considering you're the only helpful reply so far, I don't mind the self promotion
Of those three, your game seems like my best bet (for now at least. I've been keeping an eye on Our Apartment and waiting for it to have more content.)
I'll see about buying it once my bank account isn't in the negative anymore.
Finding games dedicated to flat chested female characters much harder than you would think , but games that look to contain women with small boobs as following -
https://medibang.itch.io/maken-shi-sara
https://hgameartman.itch.io/hornymagechronicles
https://pytem.itch.io/lusting-my-religion