Nightopians were Sonic Team's first Announced "Artificial-life" (A-Life) The game keeps track of the moods of the Nightopians (harming them will displease them, for example), and the game features music engine that changed the background music (BGM) depending on the mood of the Nightopians in that specific level changing tempo, pitch, and melody. When two Nightopians touch, there is a chance that an egg will appear. By paralooping a Nightopian, you will kill it, and lower the mood of every other Nightopian in the level, and drill dashing near one will cause it to be afraid of you, and will lower that specific Nightopian's mood. Nightopians will either follow you, run away from you, or be completely indifferent to your presence, based on their mood. If one is skilled enough, and has the pat