This is definitely a children's book, but I must be a child as I really enjoyed this.
This is the second book about Anne Droyd and her friends Gezz, Malcolm and Luke. I haven't read the first book, so wasn't quite sure where Anne came from or why she was with Gezz, etc, but to be honest, I just accepted she was there and it didn't detract from the story.
I really liked the character of Anne. Being a robot / cyborg and learning everything as she went along meant she would say exactly what she wanted to ask. This often got her into trouble, but I'm sure everyone would love to ask the questions she does.
The story did evolve into being a bit scary towards the end. I was thinking this would make a lovely family movie, with a bit of parental guidance for the end.