Because of the game's unique crossover nature, certain characters will often have special dialogue whenever they are paired together. For instance, Doc Brown (voice of Christopher Lloyd) of Back to the Future (1985) and The Doctor (voice of Peter Capaldi) will critique each other's mode of time travel transportation.
This is the first time that Chris Pratt plays two different characters from two different franchises in one story. His roles are Emmet from The Lego Movie (2014) and Owen Grady from Jurassic World (2015). When paired together, they might have an interesting conversation.
For the Doctor Who property, the only actors to reprise their roles from the show are Peter Capaldi (Twelfth Doctor), Jenna Coleman (Clara Oswald), Michelle Gomez (Missy), John Leeson (K-9), John Barrowman (Captain Jack Harkness), Strax (Dan Starkey), Madam Vastra (Neve McIntosh) and Nicholas Briggs (The Daleks and Cybermen). The other Doctor Who actors' voices are archive audio.
While the developer was able to get the license to "The Simpsons" characters in the game, they were not able to afford to bring in the original actors to reprise their roles. Therefore, the dialogue of Homer and Krusty are pulled from clips of actor Dan Castellaneta from the series, while Bart Simpson makes no sound at all. The Simpsons Level Pack level is based on the episode The Mysterious Voyage of Our Homer (1997)
The Fourth Doctor is the only incarnation of The Doctor that has two TARDIS interiors in the game. His second TARDIS console room is based on the Secondary Console Room seen in Season 14 and can be accessed by entering the TARDIS on the fourth consecutive day in a month (the 4th, 8th, 12th, 16th etc).