If you're after fun, escapist, Kennedy-era entertainment with a WB vs. AIP budget, sit back and enjoy "Palm Springs Weekend" for what it is: A bunch of kids (most of whom will never see twenty again) invading the popular resort community for the weekend, getting into all sorts of romantic trials and tribulations, with the inevitable happy ending.
Troy Donahue, then at the height of his fame, is the nominal hero of the story, a nice young medical student affectionately called "Dr. Jekyll." He has remarkably little to do, however, and it's the more colorful supporting characters who keep your interest through the film: Jerry Van Dyke as Donahue's wackyzanynutty best friend, Robert Conrad (just pre-"Wild, Wild West") as the particularly slimy heavy of the piece, Ty Hardin as the rodeo cowboy turned football hero (He's got steer horns affixed to the front of his car. You know the type), Connie Stevens as the "good girl" who gets in way over her head when she falls for Conrad, and Jack Weston and Carole Cook providing love among the oldsters as the boys' football coach and a local hotel owner, respectively. For the obligatory musical interlude, we have the Modern Folk Quartet performing in a nightclub sequence. See if you can spot a young Cyrus Faryar among the latter.
Norman Tourog's direction is appropriately easy and breezy, and the screenplay is by the young Earl Hamner, Jr. ("The Waltons"). Check your brain at the door and get in the mood for some early-60's-style fun. You'll be glad you did.