Well then im not missing out on anything
Nope. And, even though many folks did not comment, rest assured that Galaga '88 ('90) is well-loved by countless folks. It is such a polished, fun wonderful version that many folks have spent countless hours playing it.
Shadow of the Breast on Genesis sucks unless you play the japanese one, and even then the PCE one pisses all over it.
It looks like I may find the MegaDrive version for Shadow of the Beast if it really is better (as you explained). I had no idea the versions were so different. I still remember print advertisements for the Genesis version and thinking (this was before I played it) that it seemed to capture the essence of the Amiga version.