You can still shade in this manner and have it look lovely zoomed in, especially if you use the shapes of the solid clusters to suggest more detail than is actually drawn. I think it's more pleasing and less flat than an overload of detail, and less distracting from gameplay.
Pistachio's response gave me a rather sad thought: I'm afraid you might end up in an Auro situation here, where viewers will think the art "looks pixelated" rather than like pixel art, because it's not taking advantage of its medium, but rather fighting against it. Your art looks like it's high-res art that's been pixelized; you're not doing anything with the art so far that wouldn't be better (and possibly faster) in HD or vector art. Your art is full of large shapes with angles that don't work great in pixel art, it has lots of noisy details that would be easier to make subtle and more natural without PA's limitations, it's full of slight variations of colours that look like they want to blend smoothly but aren't allowed to. Where you do have details that do look native to the medium, like the little 1px thick grass blades, it looks noisy and artificially straight, high-res art would give you more flexibility.
I'm not saying you shouldn't use pixel art for the game, but consider
why you're using it, whether it's really helping the game look better, or holding you back.
If you're certain you want or need to make it pixel art, then consider its limitations and make use of them, play up to the medium's strengths by adjusting your visual style. Pixel art is great for:
- Horizontal, vertical, and 45-degree lines (1:2 lines can work well when there's no banding accompanying them, like there currently is in the spears).
- Creating ambiguity for viewers to fill in, take advantage of that by not trying to draw all the details, and by creating edges on your tiles that read like different things depending on which tile they're next to.
- Custom palette variants, which can be created quickly since there are relatively few colours, so take advantage of palette swapping instead of just using colour overlays for effects like weather and night, custom palettes can always be made to look better; palette swapping can be done in almost any engine via shaders.
There are probably other things I'm failing to think of, too.
Right now you're in a sort of uncanny valley of pixel art, but you have many options for remedying that.