Figured it was about time to go over our internal naming conventions. As we don't have preview images of the scenes in unity, the names need to be as clear as possible in describing their contents and function.
Intro levels introduce new mechanics, and serve to demonstrate how that mechanic works.
Edu levels teach the player techniques involving a mechanic. For example, Edu_Repulsion_2_Buildup teaches the player how pushing multiple corpse-blocks into a repulsion beam can create a 'brace,' allowing them to cross through the beam braced by these blocks, rather than being pushed along it.
The other three level categories form the game's actual puzzles, the levels that challenge the player to solve it themselves rather than existing to show the player something for educational purposes (though most Intro and particularly Edu levels still involve some element of problem-solving). Puzzles are divided based on difficulty between easy, medium, and advanced. Easy is a recently-added category – you might note earlier level lists were all Med or Adv, many of these levels have now been recategorised into the three-difficulty system.
The other important element—perhaps the most important element in the whole filename—is the letter abbreviations, which list the mechanics used in each level. These tell us quickly the necessary context for the level. For example, the level Med_CR_Stairway cannot be placed before Intro_Carry, the level that introduces the player to the 'carrying' mechanic. It also prominently involves the 'repulsion' mechanic, so we are reminded to be careful of putting it among too many other repulsion levels. As a medium-difficulty level involving advanced mechanics (carrying), we know that it's a good choice for a late-game 'filler' level, providing a mental break between more challenging late-game puzzles.
Once we've polished a level to our satisfaction and found a place for it in the level sequence, it is moved from the Polish folder to Final and given a number prefix. Med_CR_Stairway is currently in the playtest builds as 36_Med_CR_Stairway. (I should mention that these are internal names, for our organisation only. The player doesn't see any level names, only thumbnail previews and level numbers)