The principle actors from the movie contributed additional dialogue that wasn't in the movie.
An unlockable character is R2-KT, an astromech droid named after Katie Johnson who died of brain cancer. Her father Albin Johnson, is the founder of the 501st Legion, a Star Wars fan organization. R2-KT, which is colored pink, has made appearances in Star Wars: The Clone Wars and Star Wars: The Force Awakens.
This is the first LEGO Star Wars video game to come out since the release of LEGO Star Wars III: The Clone Wars five years previously and the first of all the LEGO Star Wars video games to feature actual voices instead of the regular iconic mumbling.
WILHELM SCREAM: When Han Solo shoots a stormtrooper.
J. J. Abrams (Director of The Force Awakens) and Kathleen Kennedy (Head of Lucasfilm Ltd.) can be seen in their LEGO Minifigure form in several cutscenes and moments throughout the story missions, including chatting in front of a green screen in a secret room aboard The Finalizer, and in Maz Kanata's castle. Once the player completes all Force Awakens story missions they are unlocked as playable characters.