Music is fine, gameplay should be good as usual, but I hope they reduce the importance of crafting.
Taking the next step is going to be the most difficult thing. Needs an overarching story that connects it to RotN and gives it some more value. The franchise needs the epicness of a multiple century-lasting struggle between the forces of good and evil but without being forced in rigid dichotomies such as Belmont-Dracula. I think not trying to make the Curse of the Moon events canon was a mistake. I also think they need to figure out a way to bring back popular characters, even if it involves time-traveling sheenanigans.
The other problem is visuals, the aesthetic is on point and much better than the overdesigned mess that was RotN, but they are still doing something wrong in the lightning department or the shaders. They could also increase the saturation a bit.
I really want Bloodstained to surpass the cash in that is Belmont's Curse.