Fun game
This is definitely a fun game and for the most part I enjoyed playing it because the level designs were pretty good. It's quick paced, takes skill and reaction time, and is well designed and decently programmed. All around, it's a good game.
However, if there's one thing you should take a look at, it's nerfing that damn Phantos. Literally 100% of my boss related deaths were when I tried for new characters and Phantos was out. I can forgive the fact that he can turn on a dime, I can forgive that time slow doesn't slow him down, I can even forgive how fast he moves, BUT 90% of my deaths to him were because he spawned right on the boss as I delivered a hit to it or right on top of me as I was dodging a projectile from the boss. It's incredibly incredibly frustrating to deliver the last hit to a boss just to have him spawn there right as I hit, or to dodge a projectile and have him spawn right on top of me.
A good idea would be to do a getPosition on the cursor and based on the x position of it, spawn him on one side of the screen or the other. Or, to further prevent him spawning on top of the player, spawn him at the bottom or top and have him fly through the y axis based on how close the player is to the screen's edge.
Honestly, he's the only thing that breaks this game and takes out the skill required to beat the game because of his incredible ability to spawn right on top of you.
Anyway, I've complained enough, good work on the game, it was fun to play