Nice concepts here, and the lineart is A-OK. An area you'll want to work on is your shading, particularly in regards to metals. You use a lot of dithering, which is a commonly misused technique, particularly in newer artists. I suggest you try smoothing the shading out a bit. Dithering is good, it adds definition and texture, but in your case sometimes is causing a messy "checkered" look that is easy to avoid.
Keep at it and you'll be whipping out beautifully shaded work in no time.
The cake is a lie.