The sequel is more of the same, in fact many of the bosses / enemies / spririts make a come back, but it goes above and beyond offering more content: 85 spirits instead of 65, more levels, more bosses. It also does a good job at focusing on the fun parts, for instance it hands out the dashing ability much earlier on, and it also becomes much more challenging in the late game.
I found that the late game overstaid its welcome however as it dicks the player around many areas that re-use locations and enemies from previous levels without offering much if anything new until the very last area.
The backtracking felt also less rewarding as, except from a few exceptions, coming back with a new ability was mostly for stuff that weren't useful or even just chests with coins in them.