The game is over when time runs out. But Green Essence - only found in Ninja Races - adds extra time to the clock. Use the extra time wisely!
Purple Essence grants Ninja Speed - a special mode that only appears in a Ninja Race. The Combo Kill Gauge (see below) does not go down while you're in Ninja Speed mode, so think about how best to use it.
The Combo Kill counter will go up as you kill enemies one-after-another. The higher the combo kill, the more damage you do, so take out your next enemy before the gauge runs out. Keep the combo kills going until the very end!
White Essence only appears in Ninja Races and grants a boost to the Combo Kill counter.
Watch out for how long you have left in the Combo Kill gauge. Once it's out, the damage you do goes back to where it started.
