review for Conquest of the Planet of the Apes on AllMovie

Conquest of the Planet of the Apes (1972)
by Brian J. Dillard review

Abandoning the humor of the previous and best installment in the franchise, the grim fourth Planet of the Apes film finds new director J. Lee Thompson pushing for social relevance at the expense of entertainment. This muddled allegory about an intelligent ape issuing a call-to-arms to his enslaved kinsmen, who have yet to develop the power of speech, continues the series' depressing descent into plots that must scramble not to contradict the story lines of their time-travelling predecessors. The explanation of how apes became humankind's domestic servants almost overnight stretches credibility even more than the unlikely events of the previous films. As for the actors, Ricardo Montalban must make his circus-owner character, originally a gently comic role, fit into a story line that has him slain by the authorities. Roddy McDowall, taking on a new role that shares little in common with his lovably flustered Cornelius, seems uncomfortable in his ape get-up for the very first time. Tim Burton probably had the diminishing returns of this film and the final installment, Battle for the Planet of the Apes, in mind when he chucked all but the basic premise of the original series for his 2001 remake.