Patreon is a platform where developers of free games can build a community of players who pay them a small amount of money every month to finance the development. It's the most popular platform of this type and therefore the most lucrative. It's essential for games such as Ripples being as good as they are, and continuing to exist.
Since Patreon is so popular, it has attracted the attention of religious extremists who exert pressure (e.g. via credit card companies) to get porn off such platforms. That hasn't worked so far. But what they have achieved is that Patreon throws out every game that has incest in the widest sense, or an official patch that adds incest (to close the workaround that some Steam games use for restrictive countries).
This seems to be a problem for Ripples, which I think was started before Patreon got these anti-incest rules. At the time, since (for reasons I don't really understand) incest is so popular in these games, it made financial sense to include it in your game. And it appears that the original plan was for the main character to discover at some point that one or more of the girls he had sex with in the 'present' was actually his daughter, as a result of having had sex with her mother while time traveling to the 'past'. This plan, if it existed as many of us believe, had to be revised and the plot change accordingly. This may make this set-up turn out to be frustrated foreshadowing, i.e. foreshadowing (an implicit promise of future events) that is ultimately not satisfied, leaving a bad taste for the reader. But perhaps we are wrong, or perhaps the author finds a different way to satisfy the foreshadowing. Such as by the main character's temporary belief that he had committed unwitting incest with his daughter(s), before finding out the father is someone else.