The film features an impressive cast, including Robin Williams as Teddy Roosevelt, Owen Wilson as Sacagawea, and Paul Rudd as Amelia Earhart. The characters are brought to life with a mix of humor, wit, and action. The addition of new characters, such as Attila the Hun (played by Patrick Gallagher) and Ivan the Terrible (played by Christopher Mintz-Plasse), adds to the excitement.