Robert Zemeckis previously said the film 'wouldn't work without our actors seamlessly transforming into younger versions of themselves' thanks to new tech
"It was a cool feeling," Romano tells PEOPLE. "We weren't admitting to ourselves, 'I'm a big sitcom star, and you're a big sitcom star,' but we understood this is kind of unique and cool"
Kudrow specifically credited Jennifer Aniston, Courteney Cox and Matt LeBlanc for making sure the group always practiced "respectful communication" with each other