A movie was released for a one-night showing last night (Jan 19, 2015). Unfortunately, I was unable to attend, but Ken Ham of Answers in Genesis talks about it here (there is also a link in that article to a review of the movie that’s quite good).
It is important for the secularist to tear down the truth of the Bible, even to the point of denying that it actually records history. Many secular (and, unfortunately, quite a few Christian) scholars say that the Exodus never happened as described in the Bible; it’s just a collection of myths developed over the centuries to justify the Hebrews’ taking over the Land of Canaan. They claim that no archaeological evidence supports the narrative recorded in the Book of Exodus.
They say this because they assume a date for the Exodus that is quite late (they say it happened in 1290 B.C.), and when archaeologists search around for evidence of a mass migration of Hebrews from Egypt to Canaan, they find none.
They’re problem is that they assign too late a date to the Exodus, based on presuppostions concerning Egyptian history. Here is an article that sums up the situation. See the movie, and AiG’s review of it, too, for more information.
You can also see both Wikipedia’s and Conservapedia’s treatment of the subject. (And here is Conservapedia’s discussion of the dating of Exodus).