It's not awful that's for sure, but it is hopelessly dated, awkwardly directed (almost TOO flashy in its attempt to show ALL that is seedy in NYC circa 1965). Sal Mineo is terrific but Juliet Prowse is too gawky and aloof to be convincing as the object of anyone's obsession. The oddball supporting cast helps...Jan Murray, Elaine Strich (very butch) and Stanley Beck.
Dated aesthetics, poor acting and arythmic direction. The bonus is that it deals with themes that were taboo for the time. Sal Mineo is very clearly a precursor of De Niro in Taxi Driver , his wanderings in the NYC red light district, infatuation with a stranger, and even his workout routine, all make me wonder if Scorsese, Paul Schrader or even Bernard Herrmann ever saw this mediocre but gutsy b-movie.