This shit is so damn ace. Your style is delicious like a delicious licorice caramel. That is delicious. :]~ (being a subjective truth since I like licorice.)
Anyways, your skillz in making beautiful pixel PICTURES is totally super, and your skillz in ANIMATING things just doesn't get up to that level.
When you animate effects, it's like you draw representations of keyframes that look good when viewed separate, but this is the deal:
Animation can look TOTALLY FUCKING GOOD with really ugly frames.
And to prove this, I've made a 10-minute edit to your explosions.

mine <--> yours

The only thing I did was add some relief frames after the initial 'BAM', try to give it more of an outwards BOOM instead of the animation progressing robotically ONE TWO THREE FOUR through movement and time.
Another thing you MUST do when you animate is to focus on some small particles of the explosion and make sure that they MOVE CONSISTENTLY THROUGH THE ANIMATION. Otherwise the animation will flicker and look kind of flawed. In my opinion. <3
I also added a yellow colour for BAM.
Now this might not be the result you were trying to achieve, but I'm positive that by studying this edit, you'll be able to up your skills, so that you eventually will have achieved COMPLETE ELITENESS by mastering both still frame sprite pixelling, background making AND animation (not trying to say that I have, though. But I'm willing to head that way). Good luck, man, you are one of my favourite pixelpushers on this board :]