2010's Hot Tub Time Machine managed to lace a beyond-ridiculous premise with a surprising amount of middle-age melancholy. Here the original cast (minus John Cusack) have returned to the tub, sending Lou, Nick, and Jacob into the near-future to solve a flimsy whodunit. The characters riff about messing with formula, riff about how cheap their future looks, riff about their own habits of riffing incessantly.
Despite some choice improvisations, we're given no running gag as endearing as Crispin Glover's ever-endangered arm, with Pink and company instead doubling down on half-hearted culture clash moments, red herrings galore, extra-gratuitous incidents of testicular trauma, and Lou's downright toxic personality.