This is the second video of my first time playing Sonic Adventure! This was streamed live on my Twitch: / reversetrash 0:00 Tails Story 15:58 Knuckles Story 30:29 Amy Story
I don't know if someone in Twitch chat's already told you this, but Sonic Adventure doesn't have a ranking system like later games. C levels are the levels you play through story mode. The other two kinds of levels, B and A, are available in the game's Trial Mode. Those kinds of levels vary depending on the character, but I'll use Sonic as an example: his B levels involve getting at least 50 rings when you clear the stage, and his A levels involve beating the stage in a set amount of time.