Take 2.  It helps to have the extension enabled when you try to make the images 256 colors.  These should more accurately show what you get using that extension.  Unless I messed something up AGAIN.

Might've overdid it a little.

Prompts used:
256 colors, fighting game background, deserted, plain stone floor in foreground, Castlevania in background, dusk, foreign city
256 colors, fighting game background, deserted, plain stone floor in foreground, Castlevania in background, midnight, red moon, foreign city
256 colors, fighting game background, plain stone floor in foreground, lake in background, dusk, foreign city
256 colors, side view, fighting game background, deserted, plain stone floor in foreground, ruins in background underlit by lava

Sometimes you get 8-bit looking colors (not often) or a fighting game HUD (rare).  You may sometimes get a CV-protagonist-looking person in an action pose or standing there looking towards the castle.  I tried mentioning empty plain stone floor, but I wasn't sure if that did anything.  Making the foreground a stone bridge with a lake in the background was useless (gave me a lake/river with a bridge in the distance), specifying it's a Capcom fighting game made it try to put something resembling the logo in there.  Mentioning Norfair made it try to apply Metroid things to it.  The skulls showing up was me trying to make a skull appear in the moon.
 

I also tried some stuff in Stable Diffusion.  I haven't found a pixel art checkpoint/lora that works for me.  But there's probably some combination of things I haven't tried.


It looks ok, despite goofing around and trying to use a LoRa intended for people.  Might need some inpainting to fix it up.  Used a Darkstalkers stage to get an idea of what resolution to try and generate it at.


Another random thing.  I tried to apply what I did with the Bing images to something I made (it got extended by outpainting, upscaled, pixelated/downscaled, given a 256 color palette, and edited through inpainting).


Wanted to try extending the images usng outpainting.  Doesn't work too well with the castle images because I don't know what Lora/Checkpoints are best at generating pixel art.