The intense geological activity is the result
of heat produced by a gravitational
tug -
of -
war between Jupiter's
massive gravity and other smaller but precisely timed pulls from Europa, a neighboring moon to Io that orbits further from Jupiter.
A
tug of war style affair dressed in the robes
of a riotous one - on - one fencing game, Nidhogg's mandate is twisted, but simple; you have to stab your opposite number up to the point that you can run past their corpse and reach the end
of either the furthermost east or west direction
of each stage in order to be swallowed by a
massive dragon, snake - thing.