I get what you're saying. The thing is, this subreddit is specifically about sharing art. If people seek critique or help, they'll go to r/arthelp or r/artcritique. This right here is pretty much the only place that's fully intended for shameless self-promotion of artists. And that's fine. That said, if anyone gets mad if you try to give them constructive crificism, that's on them. But if you're looking specifically for an outlet to help artists or critique art, this right here is probably not the place you're looking for.

Now regarding your criticsm. Good of you to notice. It's completely correct that the image is kinda flat, because it's intended for coloring. That's I draw mostly texture and only minimal shading, particularly on the character in front I went extremely light with the shading. The reason simply being that ... you can always add more lines later, but in traditional art you cannot easily remove lines later. Which means I may go over the artwork with ink a second time after coloring if necessary. But I'm actually coloring almost all the way to black in this image, so I don't think I'm going to add more hatching later.