Nice! Actually the list I wrote above could easily be for a Castlevania-like project as well :D
(well, apart from the bunny, but could be a bloodthirsty bunny :P )
I'm hoping you're working a similar style with the Metroidvania pack!
Certainly 32x32 begins to feel a bit tight for this asset as well!
I completely missed the undead one, I'm going to have a look right now.
May I suggest to change the cover of your 32x32 assets so that they also include a hint about how the sprites look like? I believe a lot of people, when searching for sprites, may skip that as it rather looks a game :(
Don't get me wrong: I like the covers, it's just my 2 cents since I easily missed it because of that!