Good level design and the mechanics are well integrated, there are so many different things!
I wish the game was either faster or there was an undo option (or both). Also, restart could be instant, there isn’t much reason to have to wait for it, I think.
Could be cool to have a different sprite for the vampire when he is in a state where you cannot change form (like falling) or standing in light.
I did not understand the level with the two curly spikes and seemingly no way to get up anywhere, maybe I didn’t get something about those spikes?
When in insect form, you can switch to other forms (I guess this isn’t intended as you can’t actually use them AFAIK).