Most of the Nazi thugs are played by fans who paid to have a role in the movie.
David DeCoteau, who directed four of the Puppet Master movies (Puppet Master III: Toulon's Revenge (1991), Curse of the Puppet Master (1998), Retro Puppet Master (1999) & Puppet Master: Axis of Evil (2010)) has a cameo in this movie, he plays one of the Nazi thugs.
Some of the scenes where the puppets are walking are done with actors in puppet costumes on a green screen.
(at around 17 mins) This is the first time Jester will have his surprised expression since Puppet Master 5 (1994).