Wow, that's a detailed review. Many thanks for that!
Yeah, I struggled with the level design. Cause my intention was to make a boss runner and didn't want to throw the player directly into a boss fight. I try if I can come up with some good ideas on the updated version. Although I don't know what this will be. :'D
The intended way to fight the bosses is kind of cheesy. In all cases their special attack is also their weakness, that can be used for Dracula's advantage.
And thanks for the link on pixel art. Looks pretty promising. I will check it out! :)