This book was pretty good. My kids seemed to like it a lot better than I did (although my 5yo twins were a bit scared at times). The pace lags at a few spots, and at others it is quite fast. There are some very funny parts. I would say the average 2nd-4th grade sci-fi nut would really like it. Boys more than girls (although my 8yo daughter did enjoy it). My kids loved all of the Brit-speak (although I did have to do a lot of translating for them- "Mom, what's a "natty suit"?").