Ittefaq is said to have been inspired by the 1969 classic of the same name by Yash Chopra. Indeed, there are similarities in the plot and some of its elements, but this film has pretty much a story of its own which takes an altogether different direction. The film is a very good production - it is well shot, it enjoys the benefits of high production values, from camera to sound, and above all, it is successfully suspenseful and tense thanks to good writing and direction. The most enjoyable element in the narrative style is the Rashomon effect, namely the way in which flashbacks are presented: each character recounts their version of the story and the flashbacks are presented accordingly, so we end up having a nice repetition of multiple flashback scenes based around the same incident and which are very similar, but with twists and changes in core details. This creates a fascinating watch for the most part despite the inclusion of some unnecessary proceedings, especially towards the end.
Ittefaq.is overall quite well played, although the acting is not as important as the story. Sidharth Malhotra has everything it takes to be a lead in Hindi films, including looks and presence, and acting-wise he is quite okay even if he is suited for very specific types of roles. He is just too wholesome and decent looking to be credible for anything less than a good human being and it's obviously a compliment. Sonakshi Sinha is good for the role and quite attractive even if her presence is felt much less. Needless to say, it is Akshaye Khanna who leads the film with his excellent performance as the tough cop. The film has some good turns from the character actors, by the way, especially from Ajay Jadhav who is consistently and effortlessly funny as Tambe. Overall, then, a nice thriller which I didn't like as much as liked the original. Like the original though, the film has a very poor ending. Here, I found it awfully contrived, predictable and unconvincing, but so are many other films of the genre, so let it be. It is worth watching.