On the Greek island of Hydra, the artist Jeff Koons says he finds himself “trying to play metaphysically with time.” After seasons of postponement, “Jeff Koons: Apollo” opens at the Athens-based Deste’s Project Space at the Slaughterhouse on Hydra. The exhibition presents the artist’s antiquity-inspired sculptures, plus a golden sun-shaped wind spinner and a depiction of the Greek god Apollo. The details of the exhibit were kept secret even from Deste’s founder, Jaquis Joannou, who encourages visitors to go beyond the captivating surface of these creations and discover the layers beneath. —Nyla Gilstrap