I like the concept. The gun has some really nice lines.
I just think the game is a bit lacking
Although an FPS is always fun and shooting down enemies is always great, I feel the game needs something extra.
The whole talking gun thing could be a nice companion in a story-based thing or if you had some puzzles where the gun gives you random hints and just berates you when you miss like how he cheers you on when you make a shot or streak kills.
I think you need an indication of where you're shooting other than the physical sight as well as some feedback from the enemies that they're being hit.
all in all, it's nice and I'd like to see this with more additions to it. Nice job!