Agreed with the other commenter, the sun/shadow mechanic was very cool, it took me a couple runs to get it but once I did it make my strategy much more obvious. I thought the transition to&from monochrome state was pretty seamless so I liked that.
I never actually won, but got down to like ~20 pirates which was good enough for me lol. The "mobbing" took me back to my COD: Zombies days, I spent much more time trying to knife through gaps in the mobs than actually swinging my sword lol.
I would have liked to be able to deal a little more damage, maybe using a ranged weapon instead of the melee? But like vanny said, this game was predicated on the dash more than anything, and the dash felt great!
Great foundation for the game, I can tell you've got good Game Dev chops!