Well, my main concern is that it seems that you are trying to convey shapes instead of forms. Perfectly understandable if you are still walking an early path on your artistic journey. Change of color means a change of direction in the planes that makes an object, have this in mind when shading.

Try to look at real life references and pixel art references of what you are trying to draw and study them in depth. Be really picky with said references.

As Eliddell said, be consistent with your lightsource, the stones you added to the river have some really weird highlights, this should only go on the plane that reflects the most light from the lightsource to the viewer, there are stones that have highlights in the back

The foliage of the trees seems to be made out of blobs, feel free to check this post where Eliddell, Cels and I give some advice on how to do trees https://pixelation.org/index.php?topic=64404.0

The grass closest to the camera looks a bit too much like a kids drawing, the grass on the background cave looks like fur. Again, this can be solved by looking at photos and how other artist draw grass. It's different to draw something really close and really far, sometimes textures blend so well together that they just disappear when at distance.

Same for the dirt, it just doesn't strike as dirt.

Here are a couple of great examples from different artists that you may want to check out:

https://pixeljoint.com/pixelart/139029.htm
https://pixeljoint.com/pixelart/138678.htm
https://pixeljoint.com/pixelart/88198.htm
https://pixeljoint.com/pixelart/108972.htm
https://pixeljoint.com/pixelart/76346.htm

EDIT: Please listen to Cels, his quite good at making full background pieces.

Well, simply put, it's impossible to make it look smooth on a white background without changing the sprite. (From my perspective. I may be wrong, if I am pretty please let me know why my reasoning is flawed)

But why?



Color is composed of Hue, Saturation and Value.

Mainly, our color value is what makes the sub pixel interpolation works. In the case of the black background, interpolation is seen as the following sequence:

Value   0, Value   0, Value 54, Value  0.
Value 54, Value 68, Value 95, Value 68.

In the case of the white background it looks like this:

Value 100, Value 100, Value 54, Value 100.
Value   54, Value   68, Value 95, Value  68.

In a graphic manner:



Why does this crap matter at all? You already discovered it but I'd rather explain it in case anyone would like to read about this since is a not-so-easy subject. Sub pixel needs two lines of pixels to work, pretty much like in the example image I posted. And to look smooth both lines have to follow the same sequence pattern, in this case: Dark - To - Light - To (Rinse and repeat)

What happens when changing the background to a white color is that both lines no longer follow the same sequence, one keeps following the Dark - To - Light - To but the other line start working as a Light - To - Dark - To sequence what makes the sub pixel animation to stop working at all, hence the pop.

If you pay close attention to your last edit you did (Dark Border on Light Background), it kinda pops less than the first attempt but it won't look as fluid as the other two attempts (That you totally nailed), and for what I know this have no workaround at all.

You already figured out how to use subpixel animation on a white background modifying the colors of the sprite wich for me is the only way possible. Again if I'm wrong about this please let me know!

EDIT: *Creepy, deep voice* Come to Papa @Cels, Papa can help you.

Hey those look really nice and you got rid of the umbrella diet which is good, next concept I want to introduce you is the center of balance.

Pretty much hang a pendulum from the chin of the characters to the ground, this will give you a visual cue of the current state of balance of a standing position, in this case I'll use the Poet (Bard who left his instrument at home?) to demonstrate. In this case the balance point seems to be leaning forward a bit too much, you can either move the torso a bit to the back to compensate or open the leg to our left a bit so it supports better the weight of the body (Or adjust the entire pose if you are feeling like it)



For dynamic poses this method won't work, in that case is a bit harder and less intuitive since you will have to calculate the weight, the counterweight and the point where those weights are supported, If you wanna dig into that I'd suggest making a ballerina, they do amazing poses to keep the body in balance!

I really dig the face of the male blacksmith, looks detailed yet simple, seems just like what you are aiming to! I did tried to put some extra effort on the face of the poet although not sure if it is an entire success. Also, you really should try to do hands, most of the time having all the fingers but the thumb merged works well as long as you draw at least 2 planes for the merged blob.

Again, hope this helps and this time I really want to see you implement the suggestions before submitting! *gun cocks slowly*

@Fskn That may be what I'm looking for, gonna do some testing! I do prefer Clip Paint and I think the setup is possible minus the B&W adjustment layer that somehow seems to not exist on it but in any case I can always jump to photoshop! Thanks man! <3

(By the way, did you did that gradient with sharp steps by placing two handlers on the same position? Seems like the only way I can achieve that)