What you have is rather splendid. It's tidy and bold. The fleshy parts are especially satisfying. But it could use more in various areas.
More contrast makes a mini *pop*. A little extra darkness in the recessess, and a little extra light on the edges.
Techniques involving gradual transitions (layering, blending) tend to be appreciated by a voting audience and viewers in general.
Echoing Aliengod;
Some shade around the rivets and such on the metallics, with some silver mixed into the brassy-bronze for the edges.
Black highlighting can be problematic to get ones head around, but as such it's a commonly revisited topic that a quick search with pull up various threads on for information. For simplicity, I favour a paint called Coal Black from the P3 range, although GW's new range has a pleasent bunch including one Dark Reaper colour that serves well as a black highlight.
Those tentacles coming out the flank of the torso, the highlighting could benefit from more transitionary stages between the blue-gray and white. A thinned down wash (a blue/brown mix or blue/black) could serve well as a means to get some juicy tones in the crevasses, and instead of going straight to that very light highlight do one or two along the raised edges of the whole thing, ending with that very light highlight just on the very extreme tips.
The focus area of most minis, like humans, is the face. What this mini has passing for a face area is a bit of a muddle with the colour choices. With the bone horns, yellow metallics, and the flesh choices of the person inside, they're all a bit similar. A touch more darkness in the area the person is sitting in would make them loom out from dramatically. A bit of red wash in that area could make it look a more organic blending of the person and machine parts.
So it's good so far, but could consider it a work in progress.
