This is fantastic!
1. The typography on the title could use a little something, IMO. The gradient on it is kinda bland. If you look at Sanderson, for example he doesn’t have just a straight gradient; the light and dark parts are all mixed up, if you see what I mean. I actually don’t know what that’s called! But I don’t think you want something like the grunge on Open Minds or The Harvest, because the textural detail of the broken glass is RIGHT there behind the title and I think that wouldn’t look great. Maybe something like what’s going on with Divergent? Or how Oasis has an image element (the flare) also interacting with the typography? I wonder if you can do something to get 3D with the title and the broken glass?
2. Your name and the series name disappear completely at thumbnail. This can happen on some trad books as well, but they’re not relying on catching people’s eyes with a thumbnail to drive sales, and you probably are.
3. I don’t know what to think of the gear — it’s too small to convey much and it’s very dark on an other wise light cover; it just feels very out of place to me. If you tell us what it’s for, I might have a suggestion!