Since 3.0.1 is a stability patch, it supports the massive features from the :

Optimization for online rankings and ghost data loading. 🛠️ Version 3.0.0 Context

Build your own overworld maps to link up to 40 courses.

Polished the map creation tools introduced in the 3.0.0 "Final Course Update."

All seven iconic bosses (Ludwig, Lemmy, etc.) were added.

Addressed minor bugs to improve the overall gameplay experience.