As you go through your training you will unlock abilities, these are just steps in becoming a true fighter. When unlocking a key the corresponding letter will light up on the bottom of your screen. There are blue, red and white bars on the "menu" near the bottom of the screen. The blue bar shows the number of shurikens your holding (Max 4) as you kill more enemies the bar will slowly replenish. The white bar shows your % of energy you have gathered. When you unlock the "Q" key, use this key to replenish your energy (hold "Q" down). The red bar is your health, when it runs out you will die.