Story Time :CRITICISM WANTED:

I'll start with the bad parts, since I want to end on a high note. I understand that it may be tedious, but the line quality on your backgrounds are still shaky, the more so the farther back you go. You need to place as much care on them as you do your characters. Also, you need to work a little harder on aligning your objects according to the laws of perspective. The floor tiles aren't matching up with the objects in the kitchen for example.

As for your characters themselves, I'm still seeing a few spots here and there where your outline isn't solid.

Now, about the shading: you do need to bring out more dynamic contrast, that's a fact. An easy way is to simply apply a darker, less-saturated version of the subject's color as a shadow.

Well, now onto things you do well!

You, my friend, make your characters seem alive! You have a brilliant subtlety of expression that sets you apart from lesser artists. Your style is clean and simple, just the way I like it, and everything flows well.
Also, while you still need to work on shading, your coloring is excellent. To be frank, I've never really noticed a shading issue until you brought it up because your colors are just so vivid captivating.

You are a good artist, and you're getting better all the time. I can't wait to see what you do in the future. Perhaps we can establish a partnership later on down the line.