Internally, it’s being referred to as a ‘Whodle.’ The interactive Google doodle that’s gracing the search giant’s homepage the world over today is to commemorate the 50th anniversary of cult BBC sci-fi series Doctor Who. Earlier this year, some 4,000 fans signed a Change.org petition requesting a doodle in the Time Lord’s honor. Their wish has been granted with a game that incorporates all 11 Doctors, a bunch of Daleks and the TARDIS. (Play it here.) The goal of the multi-level game that travels to different areas and eras, is to collect all the letters that spell out ‘Google’ while avoiding patrolling Daleks who are keen to exterminate any Doctor in their path — although regeneration is an option. According to The Guardian, the Whodle and the game are the product of a team of five Google employees led by transplanted Brit Matthew Cruickshank, the mastermind behind last May’s Saul Bass birthday doodle.