This game is way better than Days, hands down. Visually more impressive, Sora's sprite is bigger than the character sprites in Days, combat is the same as in Birth by Sleep(Deck Commands), and there's also a wide variety of gameplay. So far, besides the traditional KH combat, I've done side-scrolling, shooting, and turn-based. Enemies also don't take FOREVER to kill like in Days. The AI is also better in that regard, so enemies in this game have fewer health and attack more.
If you don't have this game yet, I suggest that you do.