[spoil]That's only half of it. Collecting the Red Rings unlocks more content in the Sonic Simulator, starting with 40 Rings = Playable Miis; everything subsequently gets unlocked for every 10 Rings you get from there. There are 21 Sonic Simulator Stages in total, designed in a 1 Stage, 3 Acts format - 7 Stages in total. You are given 7 Acts, so to speak, to begin with; 180 - 40 = 140, 140/10 = 14, 14 Stages to be unlocked. You are awarded a Chaos Emerald if you complete the Stage in its entirety - 7 Stages, 7 Emeralds. Once you complete all the stages, and subsequently get all the Emeralds, you can guess what happens from there[/spoil]