We understand that there can be different kinds of ways to draw an ellipse in pixel-art, but the point is that there is not real point to this. It's not an exercise that's interesting, nor is it something that will improve your skills.

You have pointed out what we should do, but not why. You're curious about how people approach ellipses? You already got your answer, why do you want us to draw multiple ellipses?

I used a Trust Widescreen tablet for multiple years, then the pen died, and instead of repalacing it, I bought a new Huion tablet from ebay and it's serving me with no issues for 2 years. No driver issues or anything. I'm not currently using Windows10, so compatibility issues may arise with older tablets.

I'm not counting my first super small Genius tablet, which served me extremely well though.

I've never had a Wacom and see literally no reason to get one, besides support. I guess when it comes to support, it's hit or miss whether you will need it. Then again, it's almost cheaper to buy a Huion and then replace it when needed rather than buy an equivalent Wacom.

That being said, I've no experience with tablets /w screens.

So, my thoughts on looking at your piece are that the characters blend too much with the background. Desaturated on desaturated just doesn't really work.  Up the color saturation and make the character pop, have him as an accent of the piece.

Besides that, the characters and building standing on the very bottom of the image looks bad, MysteryMeat proposes an easy fix to alleviate the issue.

Also, in regards to "it's not needed", the details are what make something have character. The silhuettes, I think, do not work at all. Use colors, poses and composition to draw the eye to the main character, and have the characters themselves be a backdrop, but let them be "alive".
To illustrate what I mean I'd point to any Ghibli movie. Their backdrops and background crowds are amazingly detailed and animated, and give life and, most of all, realism to an otherwise unbelievable world.

Best advice would be learn to draw anatomy with a pencil first, study and read up on different aspects of the human body. All the knowledge will translate very well to pixel-art, but learning anatomy in pixel-art will just make your life miserable. Sure, pixel-art might be more fun or easy for you, but if you want to get better, start with the basics.

Well, it's sort of hard to say what tips and tricks you'd find useful without really knowing your "skill level".

That being said, some general tips off the top of my head are:

Have a color palette/ color system for characters and background - do not use the same saturation and values on both. Usually having the character have brighter, more saturated colors makes them always stand out and make sure they don't blend with the background.

Remember that the characters are viewed from the top. When drawing the sprites from the front, they sort of form a slight V shape - just general perspective goes a long way. It's not like this is any sort of a trick, just a guideline that helps me when drawing and designing sprites.

Don't have the feet at the same pixel height, even one pixel vertical difference is felt very well. One foot being slightly in front of the other gives depth and it doesn't look like the character is standing on a tightrope.

Think of how long stuff takes to create - even if you're not constrained by time, it does help to simplify. Don't make the characters too complex, noisy, full of textures. Simple is often great, from both a work pipeline and visual stand-point.

Look around, find examples of top down characters which work and which ones don't. You can learn a lot from terrible examples when you think hard about why something looks bad and how you could improve them.

Hope something can be helpful.