Space Invaders

 was an arcade game. Ellis used the coin he stole from Si to play the game. (PROSE: Loose Change)

Ace spent half her time in her Computer Studies class playing Space Invaders. (PROSE: Timewyrm: Apocalypse)

Rory Williams had a Space Invaders t-shirt which the Eleventh Doctor thought didn't blend in very well in the 1930s. (PROSE: The Glamour Chase)