I think for the most part I see a color balancing issue. Everything feels like they're the same depth. Same level of contrast on average. Hue shifts
are present, but the saturation again is constant. is Besides the base grass and road tiles, almost everything is pretty saturated. I've checked the color palette. There's a lot of colors set to max saturation (255/ 100%). Highly saturated colors + dithering = massive eye strain. especially if you start scrolling the screen.
In games, there are visual cues as to what objects are supposed to be the background, stuff that can be traversed, and stuff that you can interact with. Application of shadows would give a certain degree of three-dimensionality to most of the objects in the scene. high saturation on interactive objects would also help with navigation for the player. Reducing saturation on land and vegetation tiles would help reduce eye strain. Most players also unconsciously treat low saturation on objects means they're either inane props or tiles they can walk on.
I've done a few edits on your image to show what I mean. I apologize for the water corrections. I haven't had that much experience working with reflective materials.

So again, desaturate the whole image, saturate only the important parts, and apply shadow/ highlights on important things to make them stand out.