Principia uses a directory to store settings and levels. Sometimes you would want to access this to manage and backup your local levels, or to check the game logs.
C:\Users\[username]\Principia\~/.principia//sdcard/Principia//storage/emulated/0/Android/data/com.bithack.principia/files/ (see Accessing Android Data Directory)The user data can be stored portably on desktop platforms if the file portable.txt is present next to the Principia executable. In this case the user data will be stored in a folder called userdata next to the executable.
community_host.txt: File for overriding the community domain used by the game. Not created by default, if file is absent the default (principia-web.se) will be used.c: cURL cookie file. NOTE: Do not share this with anyone, as this will allow them to grab your principia-web login token!data.bin: Contains miscellaneous game data such as package completion and highscore tracking.fl.cache: Cached data for the main menu featured levels list.fonts.cache & models.cache: Cache files for fonts and models respectively to make the game load faster. They will be regenerated on next startup if deleted.run.log: Log file for the latest session of the game.settings.ini: INI text file with game settings.cache/: Level cache. Temporary Lua files for editing in an external editor get saved here.lvl/: The place where levels are saved.pkg/: The place where packages are saved.sav/: Saved games that can be continued from the main menu.For cache/, lvl/ and pkg/, they are further split into "namespaces".
db: Community site levels gets downloaded locally to this namespace before they are played.local: This is where you find your locally saved levels!main: Primarily for built-in levels (e.g. the built-in puzzle package), is usually always empty in the user data folder.