Hey, thanks for trying the game and for the feedback!
I think you may have fallen victim to an intentional feature. When I first made the game one of the testers discovered that you could just hit the space bar as fast as possible and block every attack and kill every enemy. I changed the game so that if you miss an attack then you couldn't attack until the next rotation, but didn't have time to add a visual indication for this feature. Does that make sense with the behaviour you were seeing?