One claim that has always struck me as misguided is that Shadowlands is “Fantasy”, in contrast to the rest of AO’s “Science Fiction”. Then this put as a bad thing about SL.
To me, this shows that the SL stories embedded in the quests (in particular from Scheol onward) haven’t actually been read by those making the claims. If you read them, the world has a fully worked out backstory relying on “science”. It is of the rise of a civilisation to the point where they discover and abuse an energy source (“The Source”) to the extent it shatters and blows the remnants of their world into something like a pocket universe. The landscape is littered with crashed spaceships of the Xan, echoing Rubi-Ka. “The Source” appears closely related to RK’s “nanobots”. The apparent “gods” are just beings who have held onto something more than most of the earlier technology. Hecklers are indeed animated rocks, as they are indeed eating up the rocks of Shadowlands. Ghosts are echoes empowered buy the Source. Ergo is a giant computer network, and so on. Weapons are a mix of melee and guns as with RK, Garden Statues echo Whompas, boss patterns echo insurance terminals. The end boss of SL is “just” a “computer terminal” gone wrong, etc. Practically everything comes with a story. Echoes of the Shadowlands are scattered across RK.
What’s particularly interesting to me is how SL ties into the story of the Alien Invasion - the fall of the Beast is the cause of the Invasion.
One or two places the focus drifts a little too much to the fantasy, perhaps (e.g the Anansi storyline)
There are other possible criticisms of SL (too much running, too long a quests with unbalanced stages, etc.)
But, to me, Shadowlands is no more a fantasy setting than Rubi Ka.