April Fool's Day (1986) dir. Fred Walton; starring Deborah Foreman, Griffin O'Neal, Clayton Rohner (seen on Shudder)
From the height of the slasher era, this plays as a variation on Agatha Christie: Muffy (Foreman) invites several college friends to her island home for the holiday. A nasty accident happens to one of the ferrymen as the last ferry for the day gets them to the island, but once he's safely taken to the mainland, the beauty of the location calms them all. And then their hostess starts playing pranks on them, much to their amusement.
Then the deaths start happening.
Well-directed and less gory than most, this proceeds at a good pace, with a twist in its tail that, for me, works. All young performers, at least three of them have had lengthy careers, including Rohner (last seen by me in I, Madman), Foreman (Valley Girl), and Thomas F. Wilson (Biff in the Back to the Future movies). Recommended for a good Friday or Saturday night thriller.