Personally, I'm a style freak. I make sure that my sprites are not only the same bitage, but the same style. Using 2x sprites, then putting in 1x pixels makes it look very distorted. There are other ways to change expressions.
Make the "RAAAGH!" on the light-shadowed panel.
Your comics are good, but crude. You need to work on flair, fluency, and style. Just like a written paper. It's hard to describe, but there are certain things that effect the "feel" of the comic, that can completely change how someone reads it.