There are a few things that stick out to me:
1. The main character, frankly the design is very boring and static. Please understand, I don't mean to be harsh, but the character is incredibly bland. I can't tell anything about his personality from the design. The generic mouth shape. The generic hair. The generic clothing. Even the eyebrows tell me nothing. Also, they are not symmetrical (even taking into consideration the perspective shift). Also, making them visible through the hair is a convention that's been done to death in anime.
2. The main character in pumpkin form:
- same problem as the normal version - no personality, very bland
- the suit is too even (blue top and blue bottom)
- I'm not sold on your solutions to the hands and feet
- marginally better personality but again it's not clear. I know he has something going on upstairs, unlike the first guy, but I'd be hard pressed to tell you exactly what it is.
- you're not consistent with his ear shape
- the sword is very generic (this would be a good place to help emphasize the character's personality)
- better costuming
- again, no real sense of character or personality
- are his eyes really two different sizes or did you just draw them that way to keep them from being symmetrical?
- the green ptich fork that matches his pants, from a design perspective, is not ideal.
- the stance is too even.
As a whole,
- characters lack clear personality
- designs have too many cliches and lack originality
- the whole thing is very plain and unfortunately very boring.
I think that you really need to push your designs beyond just acceptable drawings. I get no sense of a design philosophy.
I hope this helps.