Puerto Rican author Roberto Ramos-Perea imagines a time-bending isle where amorous-adventure legend Casanova (Mario Marcel) is introduced to eternal-life-potion legend Count St. Germain (Hector Jimenez) by rock legend Madonna (Mary Teresa Fortuna). Casanova wants to stay desirable for all eternity, but events conspire to defeat him; the Count wants to die, but can’t because he’s drunk his own potion; and Madonna, like any material girl, “just wants to have fun.” Teatro de la Luna’s production, mounted prettily on a stylized triangular isle by director Jose Carrasquillo, is attractively performed (in Spanish with simultaneous translation on headsets) by its cast. What the company can’t do, alas, is overcome patrons’ slowly dawning realization that the author has extended what’s essentially a revue-sketch notion well past its breaking point. At 8 p.m. Fridays and Saturdays at Gunston Arts Center Theater II, 2700 S. Lang St., Arlington. $15. (703) 548-3092. (Bob Mondello)