Man, what I would not have done to get something like that when I was a kid. Hell, I'm 50 and I still want one. That would be the perfect thing to mount in a cubicle to ward off those pesky project managers.
HAHA! I got my son the non-firing version at Meijer when he was 3. It looks very similar, a tad more realistic in coloration. Feeds a belt through and makes sounds and recoils. You can even rack the charging handle and get that sound.
---I hope you don't have a cat. Our cat is the death of all nerf darts.