Sonic Advance X is a 3D Action Platformer fangame for the Sonic the Hedgehog series. Dr. Eggman has returned with yet another scheme to take over the world. However, this time he aims to conquer the world across every dimension. It’s up to Sonic, Blaze, and their friends to put an end to the doctors most dangerous plan yet. The X represents two key things, the roman numeral for 10; aka the number of playable characters, and the X-Dimension, an area that will play a major role in this games story.