Genuinely the best incest-centered VNs I have played, and one of the best in general. In a genre where plot and character personalities and archs/development are often sidelined to go straight for the sex scenes, or where said plot is made unnecessarilly complicated and the sex scenes ignored only for the former to end up flopping and being rushed at the end, this game manages to not only balance both, but also do so with excellent results.
Starting with the scenes, they are very well polished and of incredible quality among its peers, specially considering that, as far as I know, this was Perveteer first game. The improvement between the first scenes and the last ones in the game is also noticeable; Perveteer clearly put effort in learning and perfecting them as the game went on, and even the most basic ones at the beginning of the game could easily rival the best ones of the average visual novel. They also vary a lot without ever being outlandish for the characters performing them to do so, which brings me to the plot and characters.
Without delving into spoiler territory, the plot is as believable and sounded as an incest harem visual novel can get, and every single character is genuinely interesting and their respective plotlines (and eventual merged plotlines) well made. Both the main girls and the side ones have surprisingly established personalities and archs with satisfying conclusions. Even the token "best male friend character" actually has some depth to it and it's quite sympathetic, and not just a living comedy routine/excuse to make MC start thinking about their family in a sexual manner
Going further in terms of plot, your choices as the player actually do feel like they have an impact and can alter greatly the finale. Getting the harem ending is very satisfying, not necessarily because it's hard to do, but because there are many choices that basically allow you to pretty much determine what your relationship will be with every character throughout the game.
When the possibility of establishing a relationship of any kind with a girl, it doesn't feel like a pointless question that the developer itself already knows you are going to answer with "yeah, obviously I want to fuck everything that moves and is female", and instead it really feels like you could go ahead without establishing said relationship and both the side character and the plot would still make sense while also being altered through your chice. The whole pregnancy system is also an added manifestation of this; both choosing to impregnate or not a girl feel like an actual immersive choice within the plot and not "press this button if you want x content, press this button if you don't".
It still has some potential improvements, of course. While it does have some good variety in content, most of the wildest stuff does not go beyond anal and threesomes/orgies (which admissibly to the average person is already quite the thing, but come on, you now the kind of stuff that can end up in these games). That said, considering that the setting is a fairly realistic world and this isn't exactly oriented to some kind of hardcore bdsm monsterfucker, it is more than enough.
The final act does also feel a bit rushed; specifically the ending and "epilogue" feel like Perveteer planned to expand a bit more into them but chose to hurry it up a bit. It still is a very satisfying ending, however, and said "rushed" feel is barely noticeable, specially coming from an erotic visual novel, which tend to be extremely more rushed than this.
Overall, Sisterly Lust is, as I said in the beginning, one of the best VNs I have played, and Perveteer has quickly become one of my favorite devs. His next/current project, Tales From The Unending Void, is so far being not just as good, but even better than this one, and I can't wait for the finished result so I can properly rate it and add it to my list of actual masterpieces of this whole genre.
