Comic continuations, as with Big Trouble.
The big difference, to me, between those two, for instance... In Big Trouble, Jack is an ordinary guy trying to deal with really weird stuff going on. In Buckaroo, they treat the absurd as commonplace. Jeff Goldblum's character is the audience's perspective into the film -- the only one who really looks around and wonders at the things he sees (teams searching the Institute for the bad guy, Reno and New Jersey pass a watermelon in a hydraulic press; New Jersey: "Why is there a watermelon there?"; Reno (waving it off): "I'll tell ya later..." Never seen or mentioned again in the film), but for just about everyone else, they're wonderfully blase about it ("President's on the line. He wants to know is everything okay with the alien spaceship or should he just go ahead and destroy Russia?" "Tell him yes on one and no on two.") It's the same thing I love about the Hitchhiker's series. Ford's out of his depth, but "responding like an Englishman ("This must be a Thursday -- I never could get the hang of Thursdays..."). For everyone else, it's business as usual. Including the narrator. If having the absurd treated as commonplace isn't your thing, it won't land. If you like that sort of thing, it will.
--Jonah