This is a good picture! I like the clusters representing the shaggy furry texture on the wolf, the repeating of purple tones for building windows and the wolf's eyes, the green for the lighter tone of the wolf's fur as well as some building windows, etc etc. The character in the bottom-middle is framed well by the wolf, the puddle on the ground and the rampart going from one side of the picture to the other. You also have the orange highlights, complimenting the turquoise and purple colours.

 

The website has a tool that lets people check the colour count of each piece of pixelart, and it's saying your submission has over 1,000 colours in it. PixelJoint is generally a site for people to test themselves with fairly small palettes, and it seems like your original picture would fit just fine, only you've added some semi-transparent layers on top to simulate rain and haze, and that's bloated the colour count.

 

Which software did you use to put this whole image together? Do you still have the original work file (be it a .psd, or .xcf, or .clip etc), and if so, can you please reupload the image but without those billion semi-transparent layers? The underlying image would work just fine on the website (and IMO the extra layers sort of don't really compliment the finished piece).

 

If you don't have the original file anyone or you're just stuck with the final .png, we can walk you through a process of gradually reducing the colour count in that png, enough that you can still control it to a level you like, before it hits the threshold of, "this is now radically changing the colour of the clusters making up the building, windows, wolf motif etc in a way we don't want it to".