A lot of tutorials use the trick of setting the width of a red bar, killing the player once it hits 0 width...
My boss' health bar has multiple segments, 5 in fact! They're not split or anything, there's simply parts of the health bar that are different colors.
So from left to right, it goes Red, Orange, Yellow, Greenish-yellow and then Green.
Changing the width won't do much as far as I know, unless there's a way for it to cut slices off the side instead of simply crunching it up into a smaller size!
Anyway, it's your typical health bar. Once you hit the boss, the bar will go down starting from the right, until it gets allll the way to the left - that's when the boss will die.
I have no idea how to go about this, my only thought is by using a LOT of sprites - which isn't a bad idea, I'll do it if I must, I figure there's a more efficient method though.
I'd appreciate any input! Oh and on a side note - it's not required or anything - the boss has different phases, so when the boss is at full health it'll be at phase 1, at half health, phase 2, at a quarter health, phase 3, so I'll need a way to measure it's health... if that makes sense. That might help somewhat if you need any more info!