Well, the game was released today and I'll post some first impressions (PS4 version) after playing first two levels.
Game is pretty similar to the first one, controls are tight, graphics are nice and music is good. There is the "Veteran" (way it's meant to be played) and the "Casual" (pansy) mode to choose like in the first game. This time the game is split in Episodes and you can only play Episode 1 at first. Another difference is, that (at least on the first playthrough) you don't have a choice of taking other characters with you, leaving them or killing them, instead they join you automatically.
Different characters seem nice and diverse with different strengths and weaknesses. Zangetsu is pretty much the same as in the first game (at least in the beginning), he has the whip or the magic scroll bomb in the first levels. Dominique is more like Miriam in the first game; she has longer weapon (spear) and she can jump higher, but she has less health than Zangetsu. She can also do a Scrooge McDuck/Shovel Knight pogo-jumps with her Spear. She also has pretty strong magical attacks available (including one where she generates health which seems very good, maybe even OP) and a one-time-use Resurrection which brings all other characters to life (very powerful, but probably rare). I just got Robert the Marksman, who obviously has a gun (long range, but kinda slow) plus he can hang on walls/wall jump/crawl in small spaces.
The first level was quite easy, including the Boss, second was a bit harder and the Boss was quite a lot harder than the first one. All in all, if you liked Curse of the Moon, you'll probably like the sequel as well and I'm looking forward to diving deeper with it.
Oh, and there's also the co-op mode which you can choose right from the beginning, I haven't checked that out yet.