A true 101 save includes Mecha Sonic (unlocked by beating Blue Sphere as Knuckles) and sometimes the "& Knuckles" character if you enable the mod. Most 101 saves include these.

To get a 100% (or "101%") save file for , you generally need to download a completion save and place it in the game's persistent data folder. 1. Download the Save File

Unlike the base game, achieving true "total completion" in Sonic 3 A.I.R. involves more than just collecting all Chaos and Super Emeralds. A completionist save typically features: All Achievements