Your greens of the sides don't match up well enough with the green of the jetpack, or whatever that would be haha. Maybe try using gray's on the outside, and the text should be reworked, and you used too many fonts.
Dude its a pop-out sig I have not seen one of them in ages. The trick to these is to make it look effortless, with this render I think I would have gone with a more natural background find something in a city or some place that you like, then add this into the image over it with some effects. You did a awesome job of making him look like he is actually coming out of the image so that is something that you don't need to worry about. Another suggestion is that not everything needs to be ceneted, try creating something where the item popping out is off center. I would pick up some effects renders C4D type things to keep around in order to add some flair (it is a cheap trick, but it does work). Also learn smudging, it can and will help. Here is a tut to try ---> Try Me! Also here is an example of a neat looking pop-out sig ---> Click Me!
Ah yes, a good old pop-out. Getting back to the basics, me like. As ParisAsta said though, the pop-out itself can use some work seeing as the edges of it near the bottom are kinda raggedy. So I'm thinking to maybe choose a better render since the green blast effect doesn't look too good either when popped out. Nice tech look though