Unless I'm mistaken, I think fire_lake might be referring to a wholly unrelated first-person RPG spellcasting game project wherein the player would draw glyphs

Unless I'm mistaken, I think fire_lake might be referring to a wholly unrelated first-person RPG spellcasting game project wherein the player would draw glyphs with their mouse in order to cast spells, and then there would be a surprise later in the game based on this mechanic (which was later repurposed for The Witness).