Oh... This went downhill fast. Between the dev having no idea of copyright law and thinking custom age code is super complicated, when it's easily copy pasteable.
First, the copyright. Even if you aren't making money off of this project, you can still be sent a cease and desist, and failure to do so will result in a courtdate, where they can probably prove that your project doesn't change enough to be considered a parody. I'm pretty sure this has already happened to games on this site.
Secondly, the custom age code. Instead of trying to explain how short and copy pasteable the code is, i decided to just copy paste it here.
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define pov = Character("[povname]")
python:
povname = renpy.input("What is your name?", length=32)
povname = povname.strip()
if not povname:
povname = "Pat Smith"
pov "My name is [povname]!"
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But wait! This code is for naming your MC! Well you aren't wrong, but you can also use this code to define a character's age, like so.
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define ch1age = Character("[ch1age]")
python:
ch1age = renpy.input(What is this characters age?", length=3)
ch1age = ch1age.strip()
if not ch1age:
ch1age = "18"
pov "This character is [ch1age]."
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Get owned, dev. Just kidding, I only wanted to help you understand that renpy isn't super difficult, as long as you consult renpy's documentation and some of the other forums, custom aged characters are only a copy paste away!
All that said, I don't think I'm going to follow the progress of this game, since most dev's first game is hot garbage that ends up getting redone a year or so later anyways. Good luck though!