Kamal Haasan was renowned even back then as an exciting actor essaying varied roles in films like 16 Vayathinile, Salangai Oli while also dabbling in masala cinema such as Sakalakala Vallavan, Thoongathe Thambi Thoongathe, Kakki Sattai etc. But I seriously believe it was this film that catapulted him into the status of 
one of India’s greatest actors and also gave him the motivation and chutzpah to make career defining films such as Aboorva Sahodarargal, Mahanadhi, Guna, Kurudhipunal etc. Back in 1987, Kamal was presumed to be taking a huge risk, going in for a new look, sans the moustache, and there was a lot of curiosity as to how that would show up on screen. He was also acting in perhaps the first biopic of his career in a role that traversed the lifetime of the protagonist, with a director who wasn’t yet too well known at that time. Suffice to say, the move did pay off big time with Kamal bagging the national award and receiving accolades for his role. Even today, Kamal’s portrayal of Velu Nayakar is regarded as one of the greatest performances in Indian film history.
Mani Ratnam, despite delivering two hits in Idhaya Kovil and Mouna Ragam, the latter coming in for lavish and critical praise, was still not a known entity in the eyes of the masses. This film changed all that and established him firmly as one of India’s foremost directors. Though the movie evoked comparisons to The Godfather trilogy, it was magnificently adapted to an Indian scenario and can be considered a tutorial in screenplay and direction. The total absence of a separate comedy track as well as the casting of several newcomers like Tinnu Anand, Nasser, Karthika and 
Saranya was also considered a major risk. There are several scenes in the movie that exhibit the now hallmark virtuoso technique of the film maker. The very fact that the talent of the director shone through, despite the dominating performance of the star cast is proof of his incredible skills. Capturing the angst of Tamils in Dharavi has never been done better since.
There are several facets that made this movie great. Cinematography by PC Sriram was stellar and possibly contributed in redefining how Indian movies are shot. The usage of lighting and 
camera angles in this movie was completely new to Indian cinema. For instance, shots of two characters conversing with only one facing the camera were unseen in Indian cinema prior. If Balu Mahendra was a master at using natural light, PC was the foundation stone to the newer generation of cinematographers in using mood lighting. Art by Thotha Tharani was another highlight in the film and rightfully bagged him a national award as well. The Dharavi sets, the period details etc were critically focused upon and the whole technical crew came up with a masterstroke in this film.
Another highlight of this film (and all films of Mani Ratnam) was the music of Ilayaraja. It was exceptional and really integrated very well into the screenplay. “Nee Oru Kadhal Sangeetham” and “Thenpandi Seemayile” are couple of standout tracks that flowed with the story of the film. Even though Mani Ratnam had to trade-off with the distributors and include a masala song (as per his interviews later), the song “Nila Adhu Vaanathu” became a raging hit. The concept of theme music was quite a rare feature in the annals of Indian film history until then. The only aspect prevalent until then was a “family” song that would later be sung by the lead actors to result in a re-union. Ilayaraja’s diverse usage of the theme music was intrinsic to the film, complementing the narrative and helped propel the film to the masterpiece category. The BGM of the movie is also a textbook lesson in the art of re-recording for a film. Here is an example clip with a detailed analysis of the scene: http://manismagic.iespana.es/nayakan.htm
Even the posters and publicity stills of the film were very unique with only shots of Kamal’s Holi colored face staring at you. It is obvious that a lot of thought and care was given to the film to make it special and unique.
Nayagan is a landmark film in the careers of everyone who had a part in it. The very fact that it is still spoken about highly, is a testament to its greatness…
