My first impressions aren't great, although most of the problems have to do with playing on PC instead of console. The keyboard controls are awful, although they are configurable. I don't have a great controller to use with my PC because I never play games on PC.
My only real complaint aside from the platform is the soundtrack. It's 100% Shovel Knight, and 0% Castlevania. To be fair, I've only played the first stage, and I have to keep reminding myself this isn't actually Castlevania. But when Inti Creates's goal was clearly to make a notCV3, would it have killed them to use something similar to the NES's soundchip?
Eh, there's a ton of game left ahead of me. I'll probably wait til I get my console code before playing more of it, but I'm sure I'll end up enjoying the game overall.
Sorry for quoting myself, but I just wanted to say I've played the game with a proper controller now, and I'm enjoying it. I played up to level 6 I think, and I'm leaving the rest for later. I still don't care much for the soundtrack, except the obvious Michiru Yamane BGM for level 5 - and even that is really similar to Michiru's past compositions (the songs from The Pinnacle in Dawn of Sorrow, and the Forest of Doom in Portrait of Ruin, especially). I actually don't care much for the Lives mechanic, where you don't lose a life until you've lost all four characters. If you switch to a new character when your life gets low, then you end up with essentially three extra slim chances of survival each time you die. I'd rather respawn with all four characters at maximum health each time, at the cost of one life point. This just seems drawn out, although technically it's easier than what I'm suggesting.
What I really wanted to say is that the game is quite good, now that I've played it with proper controls. I can't hold the keyboard controls and the download code flub against the game itself, after all. If the soundtrack was as good as that of CV3, I might have to rank this game the higher of the two. At the very least it would be comparable.