The trivia items below may give away important plot points.
2 of David and Georgia Tennant's children, Olive and Wilfred Tennant, make a cameo appearance in the film playing 2 children who wreck a grocery store. Georgia Tennant makes a cameo appearance as well.
There are nine Doctor Who alumni- David Tennant, Peter Davison, Georgia Tennant, Nina Sonysa, Don Warrington, Sarah Parish, Ingrid Oliver, David Warner and Faye Marsay. They played the Tenth Doctor, the Fifth Doctor, Jenny the Doctor's Daughter, Trish, President of Great Britain from Pete's World, the Empress of the Raccnoss, Osgood, Prof. Grisenko and Shonya respectively. And also this would the the fifth time that both Sarah Parish and David Tennant have filmed together.