PPP4e is the main game file, and also contains the intro, ending, and cutie mark parts.
Unlike the Minty Fresh games, Minuette's sprite and all the levels are included in the game's files.

CS2-4 are cutscenes that were too large to fit in the main file without running out of memory, so they are loaded as external files. FireBG is a background with the same issue.

level-editor7d is, of course, the level editor.
As the filename suggests, it's the fourth iteration of the seventh version of the level editor.
The previous 6 aren't included because this is the first version that actually works properly. :P