According to the official release notes from plasq.com, this update focused on resolving specific technical hurdles:
Detailed documentation is available through the official manual provided by plasq. Comic Life 3.5.21 for Mac & Windows Updated! | plasq.com comic-life-3-5-21-v36998-patch
Comic Life 3 provides a comprehensive suite of tools for digital storytelling: According to the official release notes from plasq