my personal analysis is that hinduism at the belt of himalayas has bit mixture of animism or nature prayers like kirats. the most idols of god n godesses in our temples does not have distinct hands, legs or other facial features, they just give the essence of related god either in stone,  rock or wood. like in animism all they worship is mother nature, soil, rocks, air, water, etc. also, the tradition of sacrifising animals has elements of animism in it.  i believe most hindus in indias r traditionaly vegeterians so theres no question of animal scarificial in festivals. and not to forget the 'dhamis' or shamans. this could be one of the major reason that many festives, rituals, cultures n traditions practised in nepal are distinct n different from hindus of other regions, that is due to fusion between hinduism and traditional animism. in ktm we can even see the fusion between hinduism and budhism in newari culture.