Great
Pretty good, here's some tips:
+ Increase Framerate
+ Muzzle Flash
+ Bullet tracers should be white or non existent
+ Make sure the bullets look they come from the gun
+ Draw the blood while zoomed in to at least 800% to make it look seksy
+ Work on an overall color scheme, with madness you'll probably want darker, more saturated colors
It looks like you took your time on this, which is great. The more time spent the better it becomes!