I've learned RPG Maker from scratch over the course of the jam, going from struggling with the map editor to low-level hacking the engine's undocumented features to implement an encounter management system that has stumped more experienced RPG Maker devs on the forums. :D Also, at my previous jams, I have tended to make artsy mechanics-as-metaphors games, but now I've made an entire content-driven game with proper scoping and planning. :-)
My game (if anyone is into weird JRPGs): https://itch.io/jam/gmtk-2019/rate/461219