If this doesn't satisfy you, Amitabh Bachchan will be seen as genie in 'Alladin', a ghost in 'Bhoothnath', Gabbar in 'Ram Gopal Varma's Sholey' and God in 'God Tussi Great Ho'.
Ask the man himself and he says that he was embarrassed when the script of Rumi Jaffrey's 'God Tussi Great Ho' came to him. Amitabh had committed Rumi at the time when he was writing the script for 'Bade Miyan Chote Miyan' that whenever he would direct a film he would act in it.
You are considered demi-God in the industry Amitabh, so what is the problem playing a God on screen? Amitabh, if we have accepted you in the other roles why not this?