Well, it added the ability to shoot up/down, so that made the game easier for sure. I would say it's funner just for the overall graphic improvements.Ghouls N Ghosts looks funner than Ghosts N Goblins.
The us of the improper word "funner" was intentional.
"Super" took the shoot up/down feature away, but added a double jump and some damn cool weapons and power ups. Like I said, this was my personally favorite, but they are all good in their own way.
Chris