I've tried to keep it as spoiler free as possible
Fan is a movie which has an excellent buzz for a non-commercial movie which stands on just the star power of Shah Rukh Khan to make people flock to the theatres. It doesn't tick any boxes of making sure it has a big opening so Fan's sole focus in theory is its reliance on excellent "content".
Overall Fan is a thrilling ride where the first half and the second half are different movies as the first half focuses on the journey of Gaurav Chandana in his quest to meet the sole purpose of his existence for 25 years but the second half is Aryan Khanna's quest to catch Gaurav.
The screenplay is written by Habib Faisal with dialogues additionally by Sharat Katariya. The beats of the screenplay do come at the right point in the first half but it could have been better if Faisal could have played with the expectations of the audience from a particular scene. Some individual scenes are brilliantly written like the one where Gaurav Chandna's parents help him win the Super Sitara award. The Madame Tussaud's scene is also played out really well.
Fan is an underwritten, muddled development of unrealistic proportions. The best thing about the screenplay was how they fleshed out the character of Gaurav Chandna by working on the little nuances and making the character entirely believable which Maneesh Sharma and Faisal are capable as seen by their execution of the character of Ranveer Singh in "Band Baaja Baarat". Some scenes in the second half seem stupid as they go on an unrealistic terrain. The portrayal of the Hindi Film Industry could have been better but the main focus seemed to be on the controversial part of it.
The screenplay tried to find the balance in the commerciality of the project and a good storyline and in trying to find that it lost its way in the later part of the second half. The potential of making an excellent quality film with this concept was lost but not by a great margin.
I believe that a lot would be said about the acting of Shah Rukh Khan in this movie as Gaurav Chandna as the actor has masterfully played the 25 - year old fan with aplomb. It never seems like that Gaurav is played by Shah Rukh Khan and not by another seasoned method actor. The character of Gaurav by the end of the film could have easily be felt by the audience as a negative character and make us not empathize with him but the childhood like innocence is maintained in our minds about him only due to the complex yet great performance by Shah Rukh Khan.
The supporting cast has also done a great job but are hidden in the shadows for most of the part but what should also be appreciated is Khan's underplayed portrayal of a superstar.
With only one song which is not included in the movie Maneesh Sharma has done an unusual thing for a Hindi movie. He could have easily squeezed a song here and there but he chooses not to because the movie then would have been something else.
The background score by the Italian composer Andrea Guerra is unusual as he plays with a lot of sounds in the starting which sometimes personally for me seemed out of place. Though in the later half of the movie the music seemed to have come together really well.
I can not forget the use of mirrors in this movie for example in the first face-off between Gaurav and Aryan Khanna where Khanna is shown in a single shot while the reverse shot is shown with Gaurav being reflected in the mirror showing his dual nature that we are about to witness. This is one of the many instances of a brilliant use of mirrors.
Without spoiling the climax I would like to say that the last meeting between Gaurav and Aryan is shot brilliantly well especially the way Gaurav is captured. The lights used in the scene lifts it up to a whole new level. Also, the use of negative space in the frame is utilized at the right points is appreciated.
The crisp editing of the film flows really well as it is fast-paced and the little stylish transitions like when Gaurav is returning to Delhi in a train is done really well. The use of jump - cuts is also on point.
While the film builds up Gaurav's Aryan obsession and his parallel vocation as an Aryan impersonator, it is tenaciously amusing and credible and the reason can only by Maneesh Sharma's direction. The direction in the most parts is inconsistent as it is a letdown to an extent in the writing department.