E-Man's Sprite R & D

[Virt]

I think the main thing bothering me with the goomba is the weird perspective. I mean, I know you're trying to convey depth but the one eye being so much thinner than the other is kind of weird.

Also, for the axe, I'd recommend combining colors that are similar to each other, like so:

I tried condensing the palette a bit without taking away from the shading you were trying to convey.