The movie begins with an animation prologue which tells the childhood times of Akbar Ali (Mammootty) and how he is made to a gangster. Following the prologue, we witness the titles rolling with a racy background music.
The main story of the movie begins with Akbar eliminating his rival Raghavendra Gowda, and sharing the business lead with Mani Menon (Kunchan) and Uncle Sam (John Paul), two other prominent gangsters ruling the city. The city remains calm under them, until Anto (Shekhar Menon), grandson of uncle Sam comes up with a new idea of importing used vaccines from abroad at very low rates and selling them at higher price.
Akbar, who is against the business of drugs opposes it. This causes Anto to turn against Akbar and he makes plans to kill him. In the attempt, Akbar gets injured badly and loses his wife, Sana (Nyla Usha). What follows is the comeback of Akbar to avenge his loss. Can Akbar on his own take his revenge? Rest of the plot is the answer for the same.
Highlight of the performances is none other than Mammootty himself. He enacts the role of Akbar to sheer perfection with his stylish looks and dialogue delivery. Nyla Usha as Sana has less screen space in the movie, but is convincing with her role.
Shekhar Menon is with his career best performance as Anto, the main villain. Kunchan and John Paul too have done their roles with brilliance. Rest of the actors including Hareesh Peradi (Michael), Dileesh Pothen (Vidhura), Aparna Gopinath (Lilly) and TG Ravi (Hajikka) have done justice to their roles.
Cinematography by Alby is brilliant. The frames look rich and some of the camera angles makes us just awestruck.
Music by Deepak Dev is yet another relief for the movie. BGM is well made to suit the mood of the movie. There is just one song in the movie, 'Allahu Akbar' which is a treat to the music lovers.
The climax portions of the movie are brilliantly executed which matches to international standards. The fight sequences are not those ones which we have seen in Malayalam movies. The director and stunt director deserves a big applause for the same sequences.
So, putting aside all these positives, what works against Gangster? The movie has pretty much flaws. Many of the the sequences didn't had a proper finishing. Though we don't expect anything new in gangster stories other than revenge, the script was way let loose, which needed a better check from the director and script writers. I do believe a better script could have done wonders to the movie.
On the whole, the movie Gangster works only for its different style, performances, music, visuals and the engaging climax sequences. Rest is pretty much average.