Summary: Worth watching at least once.
With Hindi movies, the main issue always has been more with the same ole ghisse pitay storylines than the details. In Kaal, the storyline is refreshingly cool ...sort of like the suspense English thriller Sixth Sense. Also, cutting down on the songs was refreshing. Only if we can ban Sameer from song writing and Anu Malik from music directing, the janta wont complain as much about songs.
As for the problems with the movie, the details of the story had more holes in it than a worn out machhar-daan (mosquito net). But like I said, the overall direction that the bollywood industry is heading is good ...the details will eventually get better with time. There were many missed opportunities - not many aerial shots, poor display of knowledge regarding animals by the animal experts, etc.
Watch it once, youll like it.