What do you mean by simple and complex? There is not necessarily more information in the single celled human embryo than there is in the single cell of the amoeba. The amoeba has a larger genome.
Different information, perhaps, but not more.
But, to have gone from the simplest one celled form to a very complex form, "different but not more" understates the reality, wouldn't you agree?
More complex "processing" perhaps, with new programs (contained where) ~ yes, that is the mystery ~ what really makes the difference between a man and a fruit fly ~ certainly not millions of genes!