The first half of the film is zany. Enormously benefiting from writer Kanika Dhillon's razor sharp dialogue & quirky characters, Amit Trivedi's music (more on this in the next paragraph) and consistently terrific performances, the film races across till intermission only to culminate in a rather underwhelming second half. Kashyap lends his trademark directorial touches that separate the film from your average romance flick. For instance, take the two sisters who show up in the background in every song sequence symbolic of the dichotomy the characters face in the film. The characters in the film are impulsive, irresponsible and messy and Kashyap treats it with the right amount of wackiness that keeps the film itself from turning messy. In the second half, however, there is a sudden dip in pace and energy. The makers, from here on, don't quite seem to know how to take the story forward, so they end it in the most unconvincing way possible.
But the real hero of the film, you guessed it right, is music magician Amit Trivedi. His intoxicating soundtrack is the driving force of the film, enlivening even the most dull portions. The album is a winning combination of brazenly original sound arrangements and simple but unforgettable tunes that may be venerated for years to come.
I'm going with 3/5 for Manmarziyan. It's a pity that the film is come undone by its daunting length and a disappointing end, but I still recommend a watch because it seamlessly blends the different departments of cinema to good effect.