There are some film genres that I’m not likely to enjoy. Torture porn is one. Costume/period dramas are another. Sci-fi/fantasies rank third.

This week, after getting a little burnt out and cranky from seeing too many movies, I found myself watching “Rise of the Planet of the Apes.” But instead of suffering through what I thought would be another schlocky remake from the popular “Planet of the Apes” series from decades past, I was happily surprised to find that this latest installment may just be the most entertaining movie of the summer.

The film stars Oscar nominee James Franco (“127 Hours”) as Will Rodman, a young science whiz who’s at the forefront of testing a new Alzheimer’s-fighting drug, AZ-112, on apes at a genetic research firm called GenSys. Franco’s presence serves notice that this film is going to be smarter than usual. While he occasionally misfires, like he did in “Your Highness,” his choice of films is usually tied to great writing.

And that is the case here. Writers Rick Jaffa and Amanda Silver spool out the scientific info with a minimum of confusing jargon while quickly establishing Rodman as a full-bodied, sympathetic character whose father (John Lithgow) is slipping away into the ether of Alzheimer’s disease.

When the top ape in GenSys’ initial experiment goes, well, ape, just before the board meeting that will approve the beneficial effects of use of the drug on humans, the program is immediately canceled and the dozen apes involved in it are killed. But one baby chimp, Caesar, has been overlooked, and another researcher convinces Rodman to take the animal home and save it from extermination.

As Caesar grows, it’s clear that his intelligence far exceeds that of humans at parallel ages. Rodman realizes that the animal has developed these remarkable traits as a byproduct of the AZ-112 given to his mother and decides to use the drug on his father, who after the treatment appears to heal immediately. Success in improving his father’s condition inspires Rodman and his boss Steven Jacobs (David Oyelowo) to launch a new, even more secret round of tests. Only this time, both the good and the bad results of their high-risk experiments are vastly heightened.
To spoil another moment of “Rise” would be a crime. Suffice to say, what follows is brilliantly planned and expertly paced jaw-dropping fun rivaled only by “Fast Five” for the craziest two hours of film this year.

Also opening this weekend is the comedy “The Change-Up.” Here, grown men act like apes en route to discovering the need to develop more enlightened behavior. Starring Jason Bateman and Ryan Reynolds as best friends since third grade, the film revives the premise of body-switching comedies that flooded theaters in the late 1980s (“Big,” “Like Father Like Son,” “18 Again,” “Dream a Little Dream” and “Vice Versa”).

The first half of the film centers on Bateman, an uptight corporate lawyer who can’t seem to get a promotion — virtually the same character he played just a month ago in “Horrible Bosses.” Meanwhile, Reynolds reverts to the crude shenanigans of his breakthrough film “Van Wilder” in playing a constantly stoned slacker whose idea of a big break in acting is landing a role in a soft-core porn flick.

Both men, of course, wish that they had the life of the other. Then one night, while simultaneously urinating in a public fountain, they both say “I wish I had your life!” at the same time, thus getting exactly what they asked for. The results are disastrous for both characters, and they realize the only way they can change back is by urinating again in the same magic fountain, which has been suddenly uprooted by the city of Atlanta and lost in the shuffle of bureaucratic paperwork.

The guys have to wait a week before finding the fountain, meaning Reynolds now has to inhabit Bateman’s body and experience married life, fatherhood and responsibility. That also means Bateman’s character can finally live out his wildest fantasies while using Reynolds’ body.

For the first half of the film, this scenario results in a tedious series of events and a slew of profanities that push the limits of bad taste. Fortunately, writers Jon Moore and Scott Lucas (the first “Hangover”) and director David Dobkin (“The Wedding Crashers”) pull off a welcome surprise in the film’s second half, during which time the two friends have to learn from their situations and become better men. This is done with much better writing, much less vulgarity, a welcome minimum of sap and a heightened commitment to the roles played by the leads.

It also helps that in the second half the main women in their lives (Leslie Mann and Olivia Wilde) are revealed as funny and multidimensional people, not mere shrews or sex objects.

Thankfully, the change-up in the film’s tone doesn’t come too late. If you are at all easily offended, “The Change-Up” is not for you.

But if you can handle all the raunchy language and behavior leading to the film’s otherwise well-done and meaningful material, it’s worth the ride.