First of all, let me say that good or bad it is different than our normal Bollywood stories. It certainly sets the 'may be coming new era' of adventure and fiction Bollywood movies.
But the movie is a miserable failure at most of the points. Lets start with music. Not a single song, you will like to remember when you are out of theater. Action which must be an important part in such movies, looks like directly taken from Hollywood movies. But again, as with the current Bollywood movies, nothing looks real. Audience can easily guess that this scene you have done with strings attached to the actors body. Moreover, when you show some over action, like two guys destroying the whole camp, you will need some extra stunts, to make it believable. But it fails to make an impression.
In the area of acting, only Sunny and Jackie has done some good job. These experience actors are good with their limited talents. Vivek still has to do a lot and Sameera (who I don't know why has any role in this movie) in fact was almost negligible. You watch her because she is occupying screen.
Coming to story, it was good except that as any other Bollywood movie there are lot of loop holes. Though it was nicely joined with Mahabharat, it seems that writer do not have deep knowledge. Just a little bit more on Kavach part, could have done better.
On direction, looks like a lot efforts have been taken on special efforts. And seems that because of this other areas remain unimproved. Some scenes like river crafting, and fight with dwarfs could have made better and realistic with just a bit more efforts. But seems like director was confident on visual effects and story line and thinks these things as secondary. At the end, it just makes an impression of a new software which fails due to major bugs.