You have a cool pixel style going, with the two by two spectrals and 45 degree lines(Reminds me of Doppleganger). Why abandon it on the faces? They look kinda noisy, even though there isn't dithering. In a collection where such harsh geometric patterns are prominent, any slight organic curve will look out of place. Especially on the faces, which are a focal point because of their brightness. So, if you apply a clean angle when shading the face, it helps refine things a bit.
How does it compare?
The square highlight on the big guy's right shoulder doesn't look right. If you moved it over a tad it would. As it is, it makes his shoulder appear flat when it really isn't.
All I really have for critique is to say to go over another pass and clean things up and refine a bit, and I know these are wip so it's sort of useless.
Cool stuff.