My little worry about the new game is that playing as Yakumo and Ryu are mission-locked. Unless they both fight the same enemy types, I wish there's an option to fight in Yakumo's levels as Ryu, and vice versa.
That was what I didn't like about the recent Devil May Cry and Bayonetta games. The characters have very different moveset and I like one of them, the other, not much. I don't really enjoy playing as the new characters in those games. Not a lot of guns + melee which what I look for in those games. But that's just me. hahaha
But in NG4, it seems both characters have similar movesets so maybe it's not a big deal.