I want to start this off by saying I think this game is a fun idea that has potential, and the criticism I'm providing is intended to be constructive.
I think the mechanics clash with each other a bit. The momentum-based movement system is fun, but does not mesh well with attack patterns that require quick and precise movement. This is doubly so when several of those attacks have knockback, leading to situations where you get hit and, unable to change your direction in time, get hit by one or, rarely, two other attacks before you can right yourself. Perhaps these issues could be alleviated by increasing the character's i-frame duration, increasing the time between attacks, or reducing the character's hitbox size.
Moreover the M1 attack is slow to come out leading to several instances where by the time the line reaches the point you want to swing form, you've already passed it and the grapple ends up killing your momentum. There, simply speeding up the attack would resolve the issue.
I really like the idea of this game, but it needs a little more refinement. When, and if, it receives it, I'd look forward to playing more.