The only thing I'll contest is that it's without rules or liable to just go "anywhere."
I don't think that's the case at all.
There's a thread of intentionality here that even I didn't think they were going for. The debate and analysis over Stamp that happened after beating the game is a perfect example of that.
@The Twilight Mexican , myself and others debated and analyzed the ending and meaning of Stamp, the final scene with Zack and just what that image of a different Stamp meant, and I was pretty certain it was just a fleeting reference to Zack as a puppy on a bag of chips to dramatically callback Zack's character.
But as he illustrated it was much deeper than that. The fact they made sure
every single illustration of that fucking dog was consistent, even in the single scene of chips that existed outside of the ending, reflects an internal and cohesive trailing of breadcrumbs to reach a single strict conclusion. And
@The Twilight Mexican (and others who agreed with him of course)
reached it based on that evidence. There was a trail of evidence and intentionality that didn't just get ripped out of their asses.
As for me, I simply didn't
want to believe that was what they were going for
But in the end, that's what it was.
Time travel isn't even out of the realm for FFVII's lore of Spirit Energy and Lifestream either. The mechanics of spirit energy enjoin with time travel quite easily and with precedent. Sakaguchi literally did that very concept in FFIX with Memoria and the Crystal World. The fact that spirits, memories, and consciousness can transcend past and present, even literally crossing time and space wasn't out of left field. All the concepts of spirit energy from FFVII, FFIX, FFX, and The Spirits Within have been explored to their fullest in the FFVII series thus far. The only one remaining up to til now was time-space travel. And here we are.
They're not just throwing whatever at the wall and seeing what sticks. Or building the lore as they go along like with Kingdom Hearts which was new and basically threading its lore with each new entry. There's a metaphysical fantasy construct that has existed with rules they are sticking to. There's an intentionality here that's undeniable.