The search engine has replaced their normal logo with one which has a procession of the Time Lords marching over the top of the letters Google to mark the shows 50th anniversary.

The second O has been transformed into a play button, which when pressed releases a dalek which zaps the word and begins the Doctor Who game, where users can choose which of the 11 Time Lords they want to be.

In the platform game the Doctor has to avoid his most famous enemy as he moves between worlds on the Tardis, and every time the player loses a life they regenerate as the next doctor.

The doodle, due grace every Google home page in the world, is the biggest the company has ever produced and is said to have been nicknamed the “Whodle” at the company.

Engineers at Google, who this summer added the Tardis to Google Street View, designed the game after a petition calling for the doodle to mark the occasion reached 4,000 signatures.

Read more at http://www.telegraph.co.uk/technology/google/google-doodle/10467052/Doctor-Whos-50th-anniversary-celebrated-with-a-Google-Doodle.html