Fun little scene. I got a bit carried away with it but i wanted to take a shot at it.
Let me point out some general things about your piece.
You used too much subtle shading and details. Color differences that your eye only picks up when heavily zoomed in. This creates an insane color count for no benefit at all.
The piece is also very dark. It is not necessary to crank the brightness slider all the way down for a dark scene.
Additionally colors were reused randomly which made it sort of awkward to recolor. You could try to create a distinct palette for one each character and/or object/materials but that only as a side note.
The poses on your characters are very stiff and anatomically...weird
you might wanna look into learning character poses to get a more dynamic and authentic feel for it.
I'm not even sure i could make out that those were brick walls, those look sort of like wooden planks to me. Personally i like to avoid repeating patterns like that, and if, i make them subtle enough to not catch the viewers attention as much.
Glass, well, i never worked with glass or reflections, thus it looks weird. Hopefully someone else can give some better insight with this.
Finally for the animation, your's is very uniform. it takes less than a second to realize its a repeating pattern and after that it gets annoying to look at with all the blinking. Try to get some variety with the timing in there to make it look more dynamic.
For the light itself, it is a very stark contrast which makes it even more of a burden for the eyes. Careful with strong flickers like this, try to be more subtle.
Animated comic sounds wicked though, looking forward to it!
