I'll probably stick with the one's I have currently, as I don't want to snub my current spriter.
The eyes look very good to me (more realistic for some reason, probably the lack of outline around the whole eye). The shading is pretty good as well, but perhaps use more of the lightest shade of purple? The spikes are good but look a little...off (idk exactly how). Also, it's not perfectly round, which would be ok for more natural-looking pokes, but this is based off of a plasma ball.
Hopefully this helps. I'm not an artist myself (you should see my original sprite for this before I found a spriter...lol), soI don't know exactly what I'm talking about...
I tried to edit your starter and see if I could make it look better. Not sure if I succeeded. If you want you can use (if you're not gonna use can you tell me why it's not good enough? I'm trying to learn some spriting).