This game is a favourite of mine, the "let's go 'round again" ending notwithstanding. I've played through it a number of times recently on GBA (both through the original game and the "arranged" mode with new and harder levels), but I popped in my Super Famicom cart for the first time in a while this week.
One thing that is very noticeable to me having played the Supergrafx version of the arcade Ghouls 'n Ghosts recently is how much more deliberately paced the Super NES game is. The walking speed is considerably slower, and the inability to shoot upwards (swapped for the double jump) means that patience and care are definitely needed at times, but then at other times you need to know when to take your opportunity and run into space when it's there.
The levels are also a lot more drawn out in Super GnG, with sections like the scrolling raft sequence or rotating towers being way way longer than the parts in the arcade GnG. For the most part these are imaginative and challenging enough to sustain their length nicely, but the final levels seem to be lacking a bit of inspiration--gone are the parallax scrolling and big set pieces (tidal waves, avalanches etc) of the early levels, and instead we have simple backgrounds and repeating bosses. A case of being a little too faithful to previous games in the series perhaps, but the rest of the game is still great while it lasts.