Terminator Genisys, the fifth film in the blockbuster Terminator series, started playing in theaters across the United States on Wednesday. However, many film critics have expressed disdain for the film, which includes veteran American actor Arnold Schwarzenegger's return to the iconic role that made him a famous action hero star.

According to Michael Pearson of CNN, Terminator Genisys is a reboot of the series, featuring Sarah Connor and her son John, Kyle Reese, and various Terminators into an alternative timeline. Although he wasn't involved in this film, director James Cameron thought that fans of the original film will "love this movie."

"I feel like the franchise has been reinvigorated, like this is a renaissance," Cameron said.

CNN reported that many film critics disagreed with Cameron's sentiment. One of them included Henry Barnes of the Guardian, who thought the film was "part remake, part reboot, mostly failure."

"Kyle Reese (Jai Courtney) is sent back in time by John Connor (Jason Clarke) to protect his mother, Sarah Connor (Game of Thrones star Emilia Clarke), from the Terminator," Barnes wrote in describing the film's plot. "Reese arrives in 1984 as per the original film, but - somehow (something about a 'nexus') - the timeline's altered and in this reality it's Sarah looking out for Kyle. They're aided by a version of the Terminator (re-christened the Guardian and played by Schwarzenegger) that's been watching out for Sarah since an attack on her family by the machines left her orphaned as a child."

Barnes thought that the film's rating might have affected the quality of the film. In the United Kingdom, the latest Terminator film was given a 12A certification, the equivalent of a PG-13 rating in the United States; the original Terminator film had an R rating.

"Cameron's films were unusual for mainstream cinema in that they sutured violence to character to give it meaning," Barnes wrote. "The Terminator was murderous without thought, but with cause. The gore - the body horror of the Terminator repairing an eye socket or flaying an arm to prove a point - was grounded in the story. The slaughter of humanity felt real."

However, Barnes thought this film lacked any "real sense of dread" and fear. In the original Terminator film, humans were able to tell apart robots masquerading as live beings.

"The techno-paranoid get an Apple-ish operating system (the Genisys of the title) to worry about, but a tablet can't inspire terror," Barnes wrote. "The CGI doesn't look to have evolved much from Judgement Day. The film feels soft and phony."

In Barnes's opinion, the film made him "sad."

"Risk-averse Hollywood has made a crash-test dummy of a once great franchise, simply throwing everything at it to see what it stands," Barnes wrote. "It's heartbreaking to watch Arnie execute the same old programs: the terrible robo-smile; the slang; the wear and tear of his living tissue revealing the cyborg underneath."

Barnes blamed "Hollywood's current creative stagnation" on the Terminator franchise, noting that the latest film had a sense of "desperation" to it.

"Judgment Day redefined the action genre, CGI and the star system, creating a thirst for sequels that still leads studio decision-making today," Barnes wrote. "It was a radical film, one that escaped the B-movie trappings of its predecessor by locking into a genuinely terrifying vision of mankind supplanted. Cameron wasn't scared to move on either."

Angela Watercutter of Wired seemed to give the film a negative review as well. She thought that the plot was a bit pedantic at times.

"While it's a hoot to listen to Schwarzenegger explain time travel and whatever a 'nexus point' is, each time the action stops to remind you what year it is, what year it was, and why this time this tactic is finally the thing that's going to stop Skynet, it loses steam," Watercutter wrote. "The grand plan this time is to stop Genisys, the global Google-on-steroids that becomes Skynet, before it goes online."

Overall, Watercutter thought that Terminator Genisys gives the people "what they want in a Fourth of July popcorn movie" by playing it right down the middle. In her opinion, it was a fun but forgettable film to watch.

"Should you see Terminator Genisys this weekend? Probably. It would be unpatriotic to not go watch the former governor of California shoot things for two hours," Watercutter wrote. "Is it also fine if you forget it the minute you leave the multiplex? Yes. After all, the timeline will probably be completely different for the next movie anyway."

Terminator Genisys is now playing in theaters across the U.S.