Spartan Mode is a strength and tone workout for advanced fitness practitioners. If you're new to this or are getting back to fitness after a long lay-off this should be on your horizon but you shouldn't attempt it just yet. However, for those who are further along their fitness journey it provides an excellent way to build up strength and develop the kind of solid, muscle control that helps you level up.
Extra Credit: Do 5+ pull-ups instead of 2 each time.