I have been told this is normal. We only have one pup, but he plays with us like that from time to time. Vet and trainer said it's because that is how puppies play with one another and he is falling back into that with us when he is having a lot of fun, or has a lot of energy. I remember seeing him play with his littermates, and it as comical, play biting, barking, yelping, etc. I just wish he would not do that with us so much.
I even remember shooing his brother away from him when I saw them acting like that. It made me nervous.