This is a really cool design, but executed carelessly?
There are a lot of tangents that are confusing me. When I first looked at it, I thought his mouth was open, but I realized it was his armour. Also, where his shoulder and neck meet ... to be honest, I can't tell whats going on. I'm just seeing a whole bunch of triangles.
The colors in the update make it more interesting, but they could be better. As the green pallete got darker, maybe make it more blue. As the red(its skin) pallete got lighter, maybe add a bit of yellow. Probably not good combinations, but these are just suggestions on how to make your colors more interesting.
It looks like you are having trouble with AA too. You should work from a more comfortable background color; I think black is good, it should help to see what you are actually doing. I don't use AA much, so I could be wrong. Correct me if so.
The overall sprite just seems misleading to me, but it shouldn't take much to get it to work. This looks like something from the Ninja Turtles, I swear. Or the guys from Duke Nukem ...