Newcastle airport is ok, but it's not the most exciting place in the world though. There is a small kids play area on the 2nd floor near the cafe and the pub. It's a very SMALL play area though, but if you need somewhere for them to let off steam, it's there.
There are a few shops, Boots, WHSmith, etc not a lot else, a cafe, a pub, Costa Coffee and the kids play area before you go through passport control. Once you are through passport control there is not much at all. There is a duty free shop (not very exciting), a really small WHSmith (much smaller than the one outside), and a cafe - I also think there might be an Airtours play area, but I haven't been there with Katie for a while, so I can't really remember. Basically, I would stay on the public side of security for as long as possible - there is more room to run around etc - you can go outside and look at the planes, and generally you don't feel so trapped. Once you go through, there really isn't much.
I have to say we've never missed a McDonalds - we usually get breakfast in the cafe and let Katie play in the play area for a while.
Bev