I've always enjoyed this creator's games, and it sort of makes me want to learn how to make my own with how good they are!
If anyone still needs some tips for some reason, here you go:
-In order to make lots of money, grind the girls up until they let you have sex with them, then use the VHS tape. Taking their virginity gives you extra. This might just be a placebo effect, but I seem to make more money when recording Callie and Marie. It would make sense since they're idols, though.
-Once you unlock Marie, you should use her for the rest of the game. She's overpowered, and pretty much carried me through the rest of it once I got her, even through the boss rush.
-To unlock Harmony, buy the Amiibo from the black market. As far as I know, the note doesn't seem to do anything. To unlock the Maid, beat the boss rush you get after capturing and taming Agent 3.
-The most sensitive spot for the Captain is the clitoris, Callie the ass, Marie her boobs, and 3 as far as I know isn't particularly sensitive in any other area, while the Maid seems to be particularly sensitive overall. If Harmony has any special stats, I wouldn't know as I didn't choose the "opportunity to meet you" option when it was prompted, if it even does anything. I have the amiibo and note, though.
-If you get the maid pregnant, don't push her away, or you will feel sad. Don't worry too much though, if you do you'll just have to use M-Aid.exe to fix your mistake, and you can then just reload a save. She won't remember what you did, hopefully.