First, the positives - this movie contains some decent musical performances. Sure, they appear to be just lip syncing to the actual recording, but it's still nice to see The Animals and especially one-hit wonders The Castaways in color. We also get to see Sid Haig in one of his first bigger roles.
Overall, though, this film feels more like the last gasp of the beach movie genre than anything else. I hadn't realized they were still making these films as late as 1967, and judging by the lack of enthusiasm from the cast, they can't believe it either. There are some attempts to bring a looser, avant garde approach to the film. Or maybe it's just bad film-making. There are several seemingly random montages with overdubbed voices moving the plot forward. I'm willing to give the filmmakers the benefit of the doubt and assume this is intentional, but for all I know, it could be sloppy editing to cover scenes that should have been shot or bad writing.
The film has a downbeat feel to it, nothing like the bright, perky style we're used to with beach movies. The skies over the beach seem gray and the cast seems to be struggling with depression. I'm left with the impression that by this point, pot had clearly taken over as the drug of choice on film sets, making a Frankie and Annette style of film an uphill struggle at this point.