This is pretty awesome. Did you make the gun silhouettes yourself too? What about the characters? Is everything a vector?
the p90 i did manually with vectors, but i decided it took to long and there was a prevalence of gun images with simple backgrounds that could easily be used so create silhouettes so i just grabbed them, inverse magic-wanded them and used the marquee as masks for solid colours.
virtually everything else was done with vectors, except for the characters, whom i drew with a mouse (if you look at them you can tell they're horrible and bad). what i wanted to do with the characters was give a "skeleton sheet", where people could draw their own character models based on a bunch of different poses
skeletons like this

or like how i did it:

but i decided people would've considered that too much work on their part
so i gave up