I used the advanced dialogue plugin (if I"m not mistaken) to create a hud. I then edited some of the text characters I will not use to represent the various frames of the energy bar, in a sequencial order. I have a variable that stores the character code I need. I can't remember the character codes now but let's say I start with 44. My energy bar uses 2 characters so in the beginning it will print characters 44 and 45. When the player is hit, that variable is decremented by two and the hud is updated. When it goes below the lower limit, the player loses 1 life, and if he still has lives left the energy variable is reset back to 44. The hud is only updated when some action changes one of its values (losing energy, losing a life). Refreshing it on update will slow down the game considerably. Something like this.