Thanks! I'm glad you enjoyed it and good job for getting that far!
For some music theory: The major (or ionian) scale has 7 modes which are the level names in the game. To get each mode, you just shift the starting note of the Major scale, for example, if you start on the second note, you would get a Dorian scale. Here's an image that showcases it well:
Each mode is a seperate scale and each of them have unique qualities which makes them really cool to use. Each level has it's music made with it's own scale, which was a real challenge as I don't usually use them that often (especially the Locrian one, that's honestly terrible).