what could have be a good story be destroy by the ludicrous time travel scenario . if something be alter in the past that change evolution and human never develop and the time machine would never have be build . if something from the past be bring into the present and it would have no effect on the past . i really wish film producer would run their idea past an actual scientist before finish the script . even if you suspend reality and assume time travel be possible and you have to stick to logic . otoh and ben kingsley seem to be have a great time with his over the top performance . all of the other actor seem to be do the best they could as well . it be the writing that leave them twist in the wind . back to the future handle it well .