u/TepidShark

They get to most of the scenes in the final movie and some that were shot but deleted but how they get to a lot those is different. Also the order of scenes is different and characters were eventually combined in a lot of cases. The biggest difference seems to be >!Brian eventually leaning into being the Messiah!< even though it basically ends the same including already having Always Look on the Bright Side of Life (but without the accent Idle uses in the final version).