Not sure how I can leave a review, so will say something here while also give some pointers at the FINISH of this (skip to there if you want to read some tips and console commands.)
I played this game a while a go. Now replayed the game since it's tagged as finished. Forgot most about it too. Too bad that there is so little added. Sadly this is kind of a project that I personally hate and avoid as it involves grinding for the lack of content and the slow updates, while giving a feel that you get something for your time, even if there are just a view scenes all to get more support and revenue out. Bad strategy as you loose people interest if the grind is not rewarded with a lot of content or quality/variety of provided content (more angles, fetishes, etc.)
MOTHER ROUTE -HIGHLY RECOMMEND to all Incest driven, as it involves deep dive into why she behaves so and makes decisions to her relationship to people around while also provides some soul searching and question of sin(again, real deep dive on theological level if you are familiar to sins of the forefathers)! It I usually avoid mother route in all of this games (most do not allow it and fore it on you to progress). Partially true here, but if you go for sis route you wont see much of it. HOWEVER, that being said, I forced myself to go against this, for one character was just ok enough(lingerie was most appealing and figure was just tasteful enough), though it has some similarity to the one used in some other games like Midnight Paradise, that I can't look at as it involves huge saggy tits and oversized asses, instant skip for me, but all have their own taste(thank God). Anyway, I was suppressed on pushing trough this character and was not disappointed, would not mind to expand more on side characters presented on this route, by a long shot, but that would probably miss the point the developer wanted to make and succeeded.
SISTER route. Its grind fest, that involves multiple other events, that would never develop on it's own. This is my biggest regret in game, as you corrupt and/or coerce someone instead of a self realization and decision. Adding the repeated events turns this game into a man trainer on how to be a coherent figure in a relation. This is also pointed out by your sister as the reason why she feels close to you (first time attention + gifts & coherent in action). Taking all into consideration, with you lazy ass with no shown skills or interests, lacking financial independency (gifts bought with mom credit card), pre college. It's more of a summer fling then a ongoing relationship. Honestly, would choose mom path into business and take harem route and no mom involved as a better ending or combine that and include sister. That would be a proper ending or do something with Vicky, also underdeveloped option, but at least it's there.
CONSOLE HELP. All in one, not that bad, just way to much grinding for minor gratification. Slowly added small steps like Groundhog day, but the girls remember, to an extent. So how does it work. You increase stats, per some action. Once it gets high enough, it triggers next step. Even if you max all stats, you will NOT see(or should not see) all the progress as it needs to pass some flags/achievements to progress further. I did not test it from the start but after getting into split story mother/sister route. Nots sure what happens if you max all stats from start, but the game is set to focus on sister first (5 relation per day, later 10), then as it gets high enough it involves mom, can get fast developing relation up to 15 per day for mom or sister if you make right choices(dinner got twice with support for mom or sis to get +5 on relation each time), adding yoga time with sis licking and not removing pants for extra +5 REL and goodnight not forced kiss increases lust +1, while going into parents room and choose Vicky excuse to get extra +5 with mom(this is the fastest development in steps game has to offer. Using Cheat mode with enabled console(SHIFT +O):
lust = 100
(does nothing on it's own)
emo = 100
(also does nothing on it's own)
sisrel = 150
sedpts = 15
(seduction points around 15+ triggers mom getting home and around 22+ auto trigger into personal depression and decision mom vs sis path) You have to go trough all progression with sis first prior you increase further. Have not tested, maybe you can max all out, but better be on safe side, could be alright since it requires achievements to progress further rather then stats alone. You need to go trough all choices at least once to open new ones (usually stick to them unless stuck, then go back to basic choices will have a longer more developed scene that required higher stat to unlock.
momrel = 250
vickyrel = 150
Hope this helps. I have a save file for mom, if anyone needs but with this help and console, I doubt anyone will deprive itself of the journey.