This game is pretty good! I'd say it's quite well polished with a simple core mechanic of parrying and riposte. What I'd like to point out most:
I think you did the enemy design kind well to have well telegraphed attacks even with the limitation of 2D pixels. The attacks come in with a moment's delay before you know to parry. Overall leading to very great moments on parrying multiple successive strikes at once.
However, I'd say the game was perhaps a bit too difficult, from a game jam-standpoint. Even getting through the transition to phase two (with the red attacks), the platformer phase makes it hard as you can't block mid-air (or you can, I never succeeeded if that is the case).
Nevertheless, great game!