Earlier I participated in the excellent One-Page RPG Jam 2021, the second instance of what I hope will become a yearly tradition:
I used the front and back of the page to create separate player & GM handbooks, a core focus of the game is the dynamic between the two. The GM plays as a small magical companion animal (see: anime) who secretly has nefarious intent and drags a group of teenagers into dangerous magical adventures (see: Madoka).
I'm really happy with the system as it stands now, but in creating the first playtest material it became all-the-more obvious how much upfront work is required for a new GM to gain familiarity and build content for the system. For this game to feel truly "finished" I need to clean up, formalize, and release my system errata and starter module, which is what I'm trying to do by year-end for my entry to this jam.