You still have a bunch of unnecessary colours (particularly in the dark parts of the image), like you've made some formatting error or used a photoshop tool. There's also parts where you've combined the 2X scale pixels crash with the 1X scale pixels.
Overall, this piece lacks good pixel control, and there's also a bunch of crashing colours, like dark blue or dark purple borders crashing with the brown tiles. All these issues combined makes the piece look sloppy and noisy.
There's a lot of cool stuff here though, so if you take the time to clean up these issues, it would look rather good, I think.
The image is a bit blurry, did you save it as a jpg and then changed the format into a png?
Would you mind to upload a clean of this piece in png format?
We can't apreciate the details very well and the piece looks very interesting at first look.
A problem I see is the dark background which looks like you applied a noise filter or something rather than pixeling a proper background, but I can live with it. I would suggest just changing it to a single color since it shouldn't be as important. My only real problem is the lettering which is a big issue to me since it seems like you just used a text tool. Other than that, fuck color count. Don't sweat it too much. Over time you will learn to reuse colors instead of creating more that look similar when zoomed out.
One thing about the design of the maze, I can't tell what is a door (if any) and what is a wall. Also your chests are lopsided, probably from upscaling them. Same can be said for a few of the characters and items.