Slime Rancher 2 is an enjoyable yet peculiar game. While the physiology of slimes, plorts and a number of other things are explained through science, the game lacks many other details about the origin of slimes and how they evolved over time, the lack of other ranchers besides Beatrix being physically present, and plenty of other things that don't really make sense.
While the developer of Slime Rancher 2, Monomi Park, could explain more in future updates, it doesn't seem likely since many explanations are relatively brief in the first place in both Slime Rancher 2 and its predecessor.
7 Other Ranchers Are Not Seen
While other ranchers are interacted with in a minimal capacity, they're never physically seen. If plorts are such a valuable material and ranching slimes is a lucrative endeavor, how come the conservatory is the only ranch seen in the Far Far Range?
One would think several corporations would send out more ranchers to obtain plorts for their products and provide more competition back on Earth. Of course, since Slime Rancher 2 is still in Early Access, there's still time to add them in, but going by how they weren't present in the first one, it would be best not to get your hopes up.
6 Slimes Becoming The Dominant Species
It's unclear how or why slimes became the dominant species on the Far Far Range or why the Tarr didn't overwhelm the area at some point. Was the planet overwhelmed with Tarr when it was discovered, and if so, how did that not scare off the explorers who discovered it?
Despite some areas with food being impossible to reach for slime species incapable of flight, they never evolved past their default amorphous state to stretch or grow limbs, so we'd have to assume that there's somehow almost always a source of food for them on the ground despite how much they can eat.
5 Largos Turn Into Tarr Instead Of More Complex Largos
Largos are created when a slime eats any plort it did not produce, becoming larger and taking on the characteristics of the producer of said plort. If a Largo eats a plort it does not produce, it will turn into a Tarr — an aggressive and dangerous slime that only eats slimes and produces other Tarr.
What is it in the biology of Largos that causes them to turn into Tarr, instead of either nothing or more complex largos? Maybe after eating enough different plorts, they could become some kind of Rainbow slime, basically the opposite of what the Tarr are.
4 Tarr Only Produce Tarr And Not Plorts
The Tarr are incapable of producing plorts, but since they have a diet of only slimes, should they technically be able to? Slimes only produce plorts and are technically not made of them, but one would think that a Tarr could produce a plort after eating a corresponding slime.
What in the Tarrs' biology prevents them from producing plorts alongside other Tarr? Did eating too many plorts cause whatever it uses to produce plorts to shut down or disappear altogether? It's hard to say, as we're only told how it happens and not why it happens, and attempting to research the Tarr poses a significant risk to ranchers.
3 Hen Hens Have Subspecies But Roostros Don't
Hen Hens, flightless birds that are somehow a tastier relative to the chickens on earth, have several variants depending on where they're found, such as Sea Hens, Stone Hens, and Briar Hens. Roostros, which are required for Hen Hens to reproduce, don't have any variants despite being found in the same areas.
Since Roostros can breed with any hen, one might expect some Sea Roostros, Stone Roostros, Briar Roostros, and so on to appear eventually, but for whatever reason, this is not the case.
2 Some Slimes Can't Become Largos
While most slimes can become Largos when they eat the plorts of other slimes, select slimes cannot become Largos, at least as far as we know. For Puddle Slimes and Fire Slimes, this is likely due to only being able to thrive in specific environments where Largos would not be able to be contained. Why not just add features to contain them within those areas, then?
Lucky Slimes and Gold Slimes also can't become Largos and are rarely seen, so it's difficult to know if they truly can't become Largos or if it's something ranchers assume due to their rarity.
1 Gold Slimes And Lucky Slimes Can't Be Captured
The rarest slimes to encounter, Gold Slimes and Lucky Slimes, cannot be captured by the vacpack despite being the standard size of a slime. While from a development perspective, it's easy to see why, as it would easily give you an infinite source of money, there's no real in-game reason why the vacpack can't suck them up.
For Lucky Slimes, one could assume the reason is that they're just too heavy from all the coins they've eaten, but for Gold Slimes, there doesn't seem to be any particular in-game reason that can be made as to why they are unobtainable.