while the hub world characters in wildfrost all have interesting and fun designs/personalities, i realized that after unlocking everything, there's never any incentive or reason to click on any of the buildings ever again. the hub world basically becomes another menu to click through to start a run.
i think it'd be interesting to use these characters for other features, story or otherwise, so they dont feel unnecessary after you've completed all their unlocks.
i dont have a specific idea in mind, but perhaps small story quests for each character after you've unlocked all they have to offer. they'd give you missions with challenges like "win with X card" or "kill X boss with X status effect" which would reward the player with some story bits and maybe a charm or card unlock at the end of it