Game of the Week: 2120 and books that contain mazes

I don't know if you're familiar with the Mr Gum books, but I read them with my daughter when she was seven or eight, and I don't think I'll ever get over them. They're ingenious and hilarious and weird, and they all have this lovely sense of having been written at great speed, just conjured on the spot, with jokes and characters and plots flinging themselves together on the page at the pace of the author's typing.