These are all 359 songs as of Version 3.15.0. Unreleased songs are under the Misc section.
25 song packs: 100 songs in all song packs.
48 songs in rank: 23 songs free, 25 premium songs.
192 Event songs, 11 Wave Test songs, 3 special songs unlockable with Frags.
Level cap for non-premium users is: 30
The Giga difficulty was announced during the third event of Dynamix. The first appearance of this song is Version 3.2.3 in Event mode, with GOEMON, Cryonix and 紅 featuring this difficulty.
(with one exception, being Stage5 with a difficulty of 4)