I STRONGLY agree with titi. The modeling is fair, and the concept is fine, but the textures are VERY underworked.
No offense, but I think you rushed it. Why not take some more time and add more detail. Titi's images should be a great help. Also, using cloud effects on any still surface prevents it from becoming so mono-color. Use the primary color partially transparent, and the secondary color completely transparent and use the multiply cloud effect in Paint.NET. Make sure you select the area using the selections tools first. Note that lighter colors cannot be applied to a darker surface using the multiply effect. Use normal instead. Remember to increase roughness. Feel free to repeat with different colors and different amounts.
Experiment.