X-Zone is the eighth and regularly the final Zone of Sonic Advance.
Set on some kind of orbital platform high above Sonic's world, the Zone is much like the original Death Egg Zone in that it is composed of a series of boss fights. Dr. Eggman returns with some of his most familiar boss machines:
The first two bosses are weaker than their original versions, requiring only four hits to destroy, regardless of the difficulty mode. The Egg X is somewhat more challenging. By having all the seven Chaos Emeralds and then beating this level as Sonic, you can unlock true last boss in The Moon Zone.