Honestly, I think Metal Slug is your best bet here. Download a gif and study how they did their explosion. For one thing, you'll notice smoke goes upward, yours remain in the same position. I think this could use at least twice as many frames.
Good luck!
Thanks for the feedback.
You mean in the beginning of the explosion? More detailed advice would be cool :)
While nice, I really feel it could use a lot more frames.
simple but nice, love the palette