Loved this! Loved the narrative bits (and the news reel with all you guys' names in there!) and the music.
The aesthetic of the combo slash is very epic, and very satisfying to do. The non-combo one is notably less satisfying, and even a bit difficult to use; one -- it's not immediately obvious whether I've damaged the enemies when I hit them, and two -- something about moving to the mouse cursor made it difficult for me to keep track of where Mirai was after the dash, so I'd often run into enemies thereafter. A little bit of a pause, like the combo attack has, would have been very welcome there, and added to the feeling that this is an attack, not just a dash.
But other than that, all I can say is nice job! Enjoyed this one a lot.