Because of the pandemic, I've had a lot of free time in the last couple years - so, I decided to tackle a few Japanese RPGs, mainly those in the Tales and Trails series, because only if you have a pandemic's worth of free time, you can play video games like those, and hope to actually finish them.

Add a few bad isekai anime to the list, and my brain began to overthink what should not be overthought: there's a lot of implausible elements in those works of fiction, but what if they were, in fact, plausible? For example, most old (and by old, I mean SNES and PSX) video games in the genre took place on torus-shaped worlds, due to the limitations of the consoles they ran in, and it turns out such planets could actually exist, even if they wouldn't exactly be stable.

So, if your average old school JRPG planet were actually shaped like a torus, it would act not like our own Earth, but like a toroidal planet: a planet where the days last less than 3 hours if you're near the equator, but whole seasons near the poles, where the gravity near the equator resembles that of Mars while the gravity near the poles would be closer to Earth's, etc.

Moreover, in basically all of those games, huge, wild beasts abound: even taking into account the banded zonal climates of a toroidal planet, the sheer aggressiveness and size of those creatures could be justified by an atmosphere not unlike that of the Carboniferous or the Cretaceous, with the lower gravity providing another nudge towards the development of kaiju-sized fauna.

And about your standard fantasy races, it wouldn't implausible for them to have followed a path of Darwinian evolution from a common humanoid ancestor, even though I'm kind of stuck as for how their cladogram would look like - due to the most common depictions of elves as ancient and tree-dwelling, they'd probably be a living fossil, or at least a species closely resembling the ancestral one.

Dwarves would be kind of weird if they spent enough millennia stuck in caves though, going by the most common adaptations to that kind of environment: they'd probably become albino, blind, but capable of human echolocation, with their language(s) having a lot of click sounds, like Xhosa for example.

Any other such tropes you'd like to give a realistic spin on, and/or any help, resources, etc. for such a project? :P