I'll rate this against good animations as sympathy isn't needed for starting animations imo.
If you can, find sprite explosions so the art style matches.
You also fell into the trap of "singular fights" where you animate one object at a time. Realistically, a lot happens at once, so be sure to make things correlate as needed. I doubt the robots would stand there waiting to get shot. ^ ^
Again, this IS your first animation. It's an excellent start, and I do hope you keep animating.