Writing a review/being a food and movie critic is often a tough balancing act. Either one can write a short review laced amply with sarcasm or, instead of being negative completely, give a honest view and add which department/s can be improved. It pays to bear in mind the class of movie, the hierarchy of the director/producer/actor and the general audience in mind.
For instance, one of the good movies that I've seen a few times is the English movie ' The Revanant'. Some of the reviews were punishing for the lack of depth in the story line. But if you watch the movie, it is breath taking, the landscape, the cinematography and the powerful performance by Leonardo DiCaprio. The life of the fur traders/huntsman is beautifully portrayed.
So, I would say focus on the script and story line, then the performance and locations, song and dance is good to be commented in a commercial/historical movie but may not be so relevant in a action or a spy thriller. Focusing on how the actors perform with respect to the movie story line is also important. There are some movies wherein one single character carries the entire movie ( Surya in the Singam franchise, Kamal in Nayagan, Amir in Dangal), in such movies, you should also be fair to the other characters and elements of the movie.
In short, try not to be brutally honest with a biased view based on an actor, director or production house, give some leeway to upcoming directors and new actors on the screen. Lastly, the review should imply indirectly whether it's worth spending 3 hours and 300 rupees.