What if the developers created a "World Status" menu under the Hero tab. This menu would list every Kingdom in the game if you finished the Questline or not, How many Challenges you completed/yet to complete, if you've unlocked a particular hero subclass, unlocked a particular weapon (Mana mastery/Kindoms). Summary of Kingdoms Power and Level. X/Y Troops Found per Kingdom. Some data on Mythic Troops. Etc.
This could give new players a screen "in game" to see what the need to do to obtain something, and allow then to create mini goals for themselves to unlock the next thing.
Seasoned Players could "enjoy" trying to get it to 100%