GWPs are not typical sporting dogs, and many have temperaments that are more like a german working breed (Doberman or Rottweiller) than like a retriever or a setter. Although they like people, they can be very protective of their homes and families. They probably won't let a stranger (or even a friend) into your home when you're not there. And, they may not think it is a game when you play in an agressive manner with the kids--they may feel like they need to protect the kids! We like this aspect of the GWPs a lot. Jodi always feels safe at night when she has a GWP or two in the house. No worries about intruders sneaking in!
GWPs also are not typical sporting dogs because they don't think they need to follow your directions blindly. Because GWPs were bred to work independently in the field when hunting, they are used to making their own decisions, and will weigh the pros and cons before deciding whether to do what you tell them. It is important for you to develop a leadership role with your puppy early on, so he respects you as his leader. This doesn't mean being cruel or mean--it means being firm. Raise your puppy like you would a precocious child, and he will happily do whatever you ask (most of the time.) But, if you are permissive, and allow your cute puppy to do what he wants, he will expect to do what he wants as an adult, and will be very difficult to control.