It's a really faithful remake of 1-3 so I can't really fault it for that, tho it would have been nice to have some of the 4-6 improvements (at the very least them be optional). I didn't like not being able to open the weapon menu while a bullet is still on screen, don't remember that being a thing in NES 1-3 for all the weapons.
The Wily Tower was a fun addition! Being able to customize which skills you are equipped with is nice.