So this is my first attempt at writing up alternate/more comprehensive takes on the different worlds in the "Golarion solar system". Specifically, this is my take on Akiton, in which I hopefully retain the thematic elements that made the place fun while also expanding the possibilities available in the place.
Basic Overview
In terms of basic "planetary stats", Akiton is notably smaller than Golarion. The differences resulting from this will likely not be an incredible thing to note, but might possibly be grounds for the need to make saves for adaptation (not considering magic or other means), as well as a possible source of flavor.
In terms of technology as well as general aesthetic, as noted in the most recent published piece of info about Akiton, the conditions of Akiton have contributed to the increase in development of machinery (as well as firearms) but have resulted in the planet having notably less comforts and luxuries even compared to more ""primitive"" civilizations. Combined with the fact that much of Akitonian life seems based on city-states, I think Akiton would generally have a highly industrial aesthetic, while also having an air of austerity (that is broken up by the vibrant marketplaces, the elegant retreats and abodes of the affluent and famous, and the city-state sponsored festivals).
One large aspect I would like to add to Akiton, however, would be the introduction of canals. Canals around the planet would allow for larger communities to spring up around the major canals, and give focus to the contrast between civilization and barbarity on this relatively desolate planet.
Also, many timespans have been reduced in this version, since some of them are just too long.
Akitonian Races
The major races of Akiton are primarily composed of humans, lizardfolk, ratfolk, and shobhad, with other races being minorities. Humans on Akiton have two major ethnicities-- the red-skinned natives of the planet, and the Azlanti immigrants from Golarion. The Azlanti on Akiton have rule over several city-states, some of which are along canals, and hope to form what might be the first unified empire on Akiton in a long while. Many native Akitonian humans also live in Azlanti ruled areas, however, possibly even more live in unaligned city-states or in tribal barbarity. The ysoki and shobhad are divided between cities and the wilderness, while the lizardfolk almost exclusively dwell in the wilds.
Akitonian Equipment
On Akiton, "advanced" firearms are considered commonplace. Revolvers of varying caliber and capacity (ranging from 6-8 rounds) are the preeminent sidearm on Akiton, with semi-automatic pistols on the rise. "Bolt-action" chambered rifles and repeaters are also highly common firearms on Akiton, with innovations in railgun technology pioneered by Akitonian humans (and highly preferred by Shobhad) in usage and continuing development. Due to the emphasis on preservation of materials on Akiton, automatic weaponry is not much in vogue, although rapid-fire cannons on airships and skimmerships are becoming more common.
Vehicles and some weapons on Akiton are powered by thasteron, a mineral fuel that can assume the form of a liquid or a solid depending on how it is refined. Thasteron is most commonly used to fuel vehicles, ranging from one-person sand racers to civilian vehicles to skyships. These vehicles integrate technomagical engines and have translucent crystal plates where wheels would be on a mundane car or carriage, which, combined with the energy of thasteron, allows them to hover above the ground. This same "hover" technology is also being experimented in being incorporated into both smaller and larger objects, such as smaller constructs and buildings.
Less common, though still just as important as the previously mentioned are innovations in construct creation. The origin of construct creation on Akiton can most easily be traced to the arrival of the Azlanti on the planet, and their knowledge of clockwork constructs. Since then, innovations have contributed to a new breed of construct called "robots." These robots are often clunky in construction, but have the capability to follow commands more efficiently, as well as hold more potential for upgrade (think Silver age/Golden age comics for what they look like generally). While out of the reach of common citizens of Akiton, robots can be found guarding the residences of the affluent in most city-states of Akiton, not counting the ones produced by enterprising independent scientists.
Finally, the numerous gadgets, gizmos, potions and other such sundry devices hammered together by the scientists/wizards/assorted intellegentia of Akiton find their ways into its markets as well, resulting in situations in which a set of experimental "power armor" could possibly share shelf space with a "shrink ray" and a crate of healing potions.
Setting Notes
In general, this version of Akiton is meant to evoke a slightly more "modern" take on the ""sword and planet"" version of Mars in pulp fiction. Accordingly, Akiton is divided between the gilded glamour of the city-states and the wilds of the places between. Locations on the "seas" may also exist due to the canals. PCs may find themselves alternately ambushing a gang meeting in a city-state, rushing through the deserts of Akiton on a thasteron-fueled vehicle, or battling a mad scientists' robotic armies.
Note that this version of Akiton still generally strives to be "agnostic" insofar as it relates to current published "Golarion setting" works. Feel free to expand on it or adapt it to your personal setting (I certainly have).
One thing I'm getting from this is that you're presumably unaware of is that while it's a bit of a spoiler, some planets outside Golarion have been explored in APs for 2e and have official setting gazeteers. They're brief and not of the scale you'd see in an official 2e book on the planet or even Golarion's solar system as a whole, but they exist and you don't mention them once here.
** spoiler omitted **
I actually have read that, and actually kind of mentioned some of what I saw in that book in this post (even if I was reticent to actually explicitly say it).
Btw I have do not have access to Gatewalkers. Maybe I will get that.
Note that this post is meant not only to be a more agnostic take on the place (considering we still have very little info it) but also to expand it.