The only thing I really don't like about this is the shoulders. I can see you were trying to stay accurate to the Metru build, but his shoulder joints are out too far, and not only that, they're pointing up as if he's permanently shrugging. They need to be brought in as well as down. The perspective on the Huna is also a bit off. It's mostly in the eyes, as one seems to be significantly smaller than the other, not to mention at a different angle.Apart from those, very nice work. Your style is the sort I'd expect to see on the front of a BIONICLE novel or something. And I love your coloring. The different tones used under the green are very effective.