Special effects and storyline is not bad. But usual cheap publicity stunt to show Karan as real hero of Mahabharat is used, which has pushed back its religious authenticity. Moreover Kali demon was able to wield Gandhiv in the movie. Which is against the belief of Sanatana dharma. If you want to watch it as a scifi comedy and drama then it is good, but if you want to understand story of Vishnu avatar then it is far away from epic.