The comedian Dara Ó Briain has a funny routine about video games. He talks about how no other form of entertainment purposefully withholds content until it considers that you deserve to see it. There are no books that test you at the end of the chapter to ensure you have appreciated all the themes correctly; films don't end if you fail to spot a visual gag. But this is how most games work. Which makes reviewing a game a very different experience to reviewing a movie or a book.

The big issue that I am interested in is: what does it mean for us to live with machines that are not sentient but appear as if they are? Let's start by quickly defining sentience and intelligence (at least for this discussion). We'll say that intelligence is the ability solve complex problems, handle varied input and achieve goals. An abacus is not intelligent. Sentience is the ability to feel, to have first person experience.