The movie highlights how strong Harrison Ford was in "Indiana Jones" (also 1984), and Danny DeVito’s performance is also quite good; however, Michael Douglas and Kathleen Turner don't fare so well – they seem rather unremarkable. He plays “Jack,” a charming character who assists the fictional writer “Joan” as she journeys through Colombia looking for her sister, which involves a treasure map of some sort. The story moves slowly at first, but eventually delivers a succession of visually striking and diverting action sequences accompanied by an insistent electronic soundtrack that tries to mask some truly silly lines from both actors. DeVito, playing the kidnapper “Ralph,” consistently manages to make his appearances memorable as the plot progresses toward a suitably dangerous – though unsurprising – ending featuring giant insects, a waterfall, car chases—and frequent soaking for everyone involved. You can probably imagine what it's like. It’s acceptable enough for an afternoon viewing and there is some spark between the leads, but ultimately it feels like a weak copy of something else, and the humor hasn't stood up to time either.

Source on TMDB