With the exception of a few movie references?the dialogue and one-sheet from 1984's "Red Dawn" is recalled; a romantic scene is staged to mimic 1984's "Sixteen Candles," and go-to '80s bad guy William Zabka (1984's "The Karate Kid") gets a familiar sort of role?and a handful of time-specific jokes (one girl asks what e-mail is, while a walk-on character carries a cell phone the size of a large brick), "Hot Tub Time Machine" really doesn't take satisfactory advantage of its time-travel storyline.