Amazing, but inaccurate. Artistically, I cannot dispute with this one at all. You've nailed the colours, everything.
Inaccuracies I can't help but point out:
1. Unless someone is a god-tier player, Samus should be wearing the Varia Suit by now (if this is the original Metroid) or the Gravity Suit (Super Metroid). The Power Suit would drain her health more quickly than you can say "Metroid."
2. Her gun extends to about 2/3 of her hand, if not half. I don't see it here at all.
3. Mother Brain had a visible eye. It seems to have gone missing.
All that still doesn't take away from the fact that this is an amazing piece. Keep it up!