Painting is nice and clean, with some details very cleanly picked out, so nice painting for a beginner. However what I think deducts points is the lack of shading, which creates a very flat colour and leaves the model looking 'toyish'.
Maybe try some inks and/or washes, or highlighting on areas? A black and/or brown wash on the metallic areas would work wonders for bringing out the depth of the model
I'm actually giving you a 6 because it's a very good start for a new painter. The colors are very neat and overall I like your scheme. What I would recommend is to do some washes, especially on the metal. Otherwise it looks a little too plastic.