The third instalment of the BBC's Doctor Who - The Adventure Games has just been released for free download, and it allows players to wander about the TARDIS; visiting areas that have never been seen before.

Following on from City of the Daleks and Blood of the Cybermen, the new game features the Doctor and Amy Pond in a 3D action adventure game, crafted by Sumo Digital and produced by the TV programme's show runner himself, Steven Moffat. This time though, instead of landing on a strange planet or location, the action takes place in the Doctor's own time machine. A new monster, The Entity, debuts too.

"When they asked me if I could name all the controls in the TARDIS and explain what they do, I knew that my years of obsessive nerdiness had finally paid off", says James Moran, script writer on the game and TV show, as well as Torchwood. "My inner five-year-old is shrieking with excitement".

"But that's not all - we've got new monsters, a new type of danger for the Doctor and Amy, and an area that has never been seen before. Just don't sit in the Doctor's chair..."

TARDIS is the third instalment in a series of four episodes, and is available on PC and Mac from the BBC's dedicated website: It links in with the launch engine of the other episodes, which are still also available, or can be played separately.

There are also Nintendo Wii and DS Doctor Who games due before Christmas, named Return to Earth and Evacuation Earth respectively.