Unfortunately, I never really got the chance to play a Castlevania game for more than a few minutes at a time, but from what little I've experienced, I see the similar charm, and I recognize the feel in this game. Wonderful job portraying that, while giving it its own great humor.
As for game mechanics, slow movement was my first peeve, but after I realized I could slide, and then soar with the slide-jump, my problem with that disappeared.
While I'm seeing a lot of discontent over the Ghosts, I must say I understand their difficulty, and don't believe they break the game at all. You simply need to learn how they work and how they move, and use that to your advantage.
I do notice that often when I get caught in the piston guillotine-like things, I'm in for at least 3 hearts with of damage. Perhaps this is part of the punishment of getting caught in one in the first place, but maybe it could also tell you that there needs to be more substantial temporary invulnerability right after getting hit. Definitely the designer's choice, though.
Overall, I say that the difficulty was spot on. Great challenge for the players, just as you intended, and as Castlevania tributes should be.
The control scheme for the keyboard is a little weird at first, but not at all difficult to get used to if you put a little time into it. Too many people are complaining about it, and it's really not that impossible. There are only a few actions, and learning what keys do what, even if they are arrow keys bound to attacks, it is definitely within anybody's power. Perhaps, though, if you'd like to appeal to the masses, you could include the ability for the players to remap the keys to match their preferences. That could resolve all of the complaining for the future for sure.
I very much enjoyed this game, challenge and all. You had a goal in mind, and you accomplished it and portrayed it wonderfully. I'm looking forward to the "full" version of the game. Thanks for your hard work!
-I hear that there will be a "Part 2" to this, in which the green and blue force fields will be addressed, and the gameplay will become non-linear and more exploratory. Is this going to be a re-upload/update of this game, or a separate game entirely. If it's separate, how do you get past the walls (in this game) to get to Alucard, as well as other secrets that the medals might be requesting?
-Subtitles would be a minor but good thing to include in future iterations. I and others sometimes don't have full speaker capabilities, and I missed some things that were said.
-Speech problems aside, I was able to hear some of the music, and I definitely think that there should be an ability to toggle different secret songs you collect after getting them for the first time. While I am not a huge Castlevania buff, I recognize its music and love it very much, and it would have been nice to be able to switch to it on command (because you don't have a chance to collect it again if you're using the "checkpoint" route regularly). So maybe just some way to toggle unlocked songs, if there are more that just that first one, would be a cool minor addition.
-What in the world is that little empty tower to the right of the path to Dracula? It took me a few tries to get up there, and when I finally did, I found nothing. >.> Left to a future version, perhaps?
Again, great game, and I had a lot of fun playing it, so nice job! I'll be working on 100%ing it soon!