You are on the right track in trying to make your sprite more presentable, LienPixels... however, what I am really seeing here is a sprite that does not even fit the standards of a proper 2x1 pixel-aspect ratio at all as it currently stands so far. That is why I am here to help, as I truly understand that this is your rather first time in trying to make this kind of style of pixel-art for your game project.
That said, let me clearly show you how to make your own sprites a whole lot better and *much* more convincing to fit a more suitable 2x1 pixel-ratio format in its most purest form. ^^
First, I would redraw the entire sprite all over again, this time at half the horizontal (X) size while your vertical (Y) size remains unchanged as normal. Here is how it is done using the Amstrad CPC palette that you are currently using, for example:
Now with our caveman (so much handsomer now, with even some small bits of chest hair for good measure too!!! ;) ) entirely redrawn from the ground up as our brand-new sprite for this test, all you have to do then is to change the width (X) to 200% while setting the height (Y) to just 100%, and the resize type set to “Pixel Resize” for that single object indeed, to completely avoid any blurring whatsoever. Once done, click “OK”. Here is what should be our desired result:
If you do all of that right, we should NOW see our own caveman in a much radiant form of a proper, nicer, purer, and far more coherent “2x1 pixel-ratio”-based sprite object that is absolutely ready for your game creation!! And please remember this exact entire method as was shown here in this very post now, as it also works just as well for background set-pieces (and even parallax-scrolling ones, too!), so definitely try to use this technique as often, constant, and as seriously as ever as one stepping stone forward after another in order to help you *finally* get good at last using this challenging yet ultimately rewarding new medium... it takes quite some practice and getting used to, but do not give up; you will soon get the guaranteed hang of it all to the point of muscle memory before you even know it, I promise!!! ;)
Thank you so ever very much for your time especially, LienPixels, and I sincerely hope this one tremendously helps you out rather a long way going forward into your entire game project right here for this jam!!! (^-^)=b !!