Need suggestion for my model

Artwork Works in Progress
1

With the specification given below. I have created 4 models. Any suggestion what is missing or where to improve.

Specification

Model 1

concept 4 render
concept 4 render1250×720 63.6 KB

Model 2

concept 3
concept 31250×720 73.6 KB

Model 3

render 1
render 11250×720 165 KB

Model 4

concept 5 render
concept 5 render1250×720 63.2 KB