I actually think KQ4's graphics are rather on the ugly side--at least, nowhere near reaching the potential of what 16 color SCI graphics were capable of. They don't hold a candle to Hero's Quest, for example.
I love certain elements of KQ4--the open land to explore, the day/night timer, the ghost/graveyard puzzle (minus the ridiculous broken shovel dead end) was always a highlight. The hidden bridle was terrible, among other things. Swimming out to Genesta's island was needlessly obtuse. It was definitely a "how many hint books can we sell?" type of game.