Blade
it is very easy to know when u run out of ninja. even a new player could see that without having to look at a HUD element in the top corner of their screen while trying to play @Iza
a precise meter that is visible the entire duration just sounds sensible to me. the stars are helpful during intense gameplay where you obv look at the middle of your screen, but the top-left corner can give you the whole image, thats what its for