Some spoilers and theories ahead.
Ok. This is great. I'm a bit of a time travel aficionado and the set up so far is something I've really wanted to see in a porn game setting lol.
Everything so far seems to point towards a fixed timeline scenario, which is definitely the best type of time travel story. Let's assume that the MC will go back to the past again which is a given since we've been introduced to a number of bangable girls in the past. It certainly looks like the MC is his own dad and possibly the father of like half the girls in the present timeline. This can get pretty dang interesting.
I really hope the dev doesn't get timey whimey on us by mixing a fixed timeline with alternate timelines. That's essentially how all the plot holes in time travel movies happen. Stick to one. If the timeline is fixed, whatever happened, happened, and will always happen that way. If there are alternate timelines arising form multiple universe theory, changing the past wouldn't affect the present at all. The "dynamic timelines" that we see in so many movies about changing the past to save the present are always full of plot holes because it fundamentally cannot work through the grandfather paradox.
The causal loops (chicken and egg problem) in fixed timelines are a paradox in a sense as well, but at least these stories are internally consistent. We just have to accept the fact that there is no beginning to the loop and it always was. Grandfather paradoxes are a lot messier because it tends to break the time travel rules laid out in the universe. Look at Looper. Old Joe goes on his mission to kill the Rainmaker as a kid, but the Rainmaker only exists if Old Joe goes on his mission and accidentally kills Rainmaker's mom. Young Joe stops Old Joe which means there is no Rainmaker, which means Old Joe wouldn't have a reason to try and kill the Rainmaker.