I like it, this works in Toribash!
There's a couple of things that seem to come back in your designs, which are floating part and the plastic like shading.
Whilst it's not bad at all, it misses the "oomph" for me on most designs.
There's a couple of ways to "fix" this.
First off, harder shading. This will give the idea of metal rather than plastic. The plastic feel is something I struggled with quite a bit when I textured back in the days. I was just too careful with shading. Now I shade and once I'm done I copy the entire shading group to see if it's an improvement. If it is, I continue shading, if it's not it's done.
The floating parts is something a lot of texture artists including me did back in the days. I reckon we're both quite old artists on here so we're in the same boat. Whilst I still like it, it's quite fast to make a good looking head and it gives you a lot of creative freedom it also misses a connection to realism. Back in the days of Jetfire I basically lived by floating parts but then I found out an easy way to connect parts. It's very simple, a stroke with bevel/emboss. Whilst not an idea solution, it's fast and simple. Very handy if you don't want to spend too much time.
Hit me up one time if you want to talk about texturing like the old days!
Keep it up!