Well, "finished" the game, here's my thoughts, in brief, because it's 2 A.M. and I need to sleep:
Overall, a solid base, but the progression of events is really random. For example, what's up with the "slime on the couch" quest? I had no clue what to do with it. Also, I swear I got another quest which disappeared, and I never got the tea quest someone mentioned previously. It also really feels like getting enough points to get any change in the events would really suck without the point adding feature adding in "postgame"
The explore thing kinda sucks. I don't know if I was unlucky, but the only thing I got was 5's earrings. Every other time I either got nothing, or lost what I had. One time I got two gumballs, and then a coin, and then it auto advanced, so I lost everything. Really sucked. Maybe add more good events, or add some feature where you get items automatically when you finished exploring (the hole filled floor).
The intro to the slot machine should say "enter your codename" instead of "enter your numbuh. just your numbuh" because I thought it meant the number, i.e. 25, not the full thing, numbuh 25.
For 3's costume thing, I think the game glitches, because after I changed her outfit, she's just naked everywhere. (Also, unironically, a modified version of that rainbow monkey suit she has could work as another costume. Just saying"
Does 5 have another costume? I never saw it, if so, and buying her alternate costume just gave me the cream bra, which I already found in the treehouse, and which she seemed to already have after I gave her the earrings.
The chores are weird. It seems like the only good things happen sometimes when the protag cleans and 5 searches for coins. Everything else either gives nothing, or makes the characters angry.
Speaking of which, it seems way easier to make characters angry than to make them happy. Also, the gifts for 3 are weird, candy makes her happy, I can't give her the doll, and the comic makes her angry.
As for future content ideas, I think the characters you have are good enough to go forward with, but, honestly, I'm a bit surprised you didn't have 2 and 4 get genderbent. Adds two other characters, and you could just say it was a side effect of the ice cream, or another plot. Also, maybe have the protag get affected by either the ice cream or something else, and have that segway into more explicit scenes.
Also, as others have mentioned, the ending isn't very good. It's abrupt, and making you click the link is a bit cute, but it deleting your save (supposedly, I clicked the link) when you don't is just annoying.
TLDR: Good start,look forward to see where it goes, needs some work though. Might add more after I sleep.