Glad you found it! :D But yes, I can see how it can be less noticeable that it's going down while centered since you don't have as much of a point of reference with a bar that small.
One thing I wish I had time to have improved is the indication that the HP went to 1 when transformed. Right now, it reflects as a single pixel-wide health bar, but it's not really visible with the flame effects and attacks everywhere, so it might seem like the health bar disappears. I also didn't want to play "Zelda low hearts" sound when transformed, because that would be annoying, though possibily appropriate for the non-transformed mode. :)