Very satisfying game to play, it has a lot of juice in it. From the player hitting to the music.
I noticed that you mentioned about making it more obvious when the enemies are about to hit. Tbh, I don't think that was quite the issue for me. I think the bigger concern is that there is no clear easy way for the player to defend themselves from the enemy. I see the enemy flashing, but there's nowhere to go except for through the enemy or to another enemy who is probably also attacking.
I played about 4 times, and each of my playthroughs only lasted about 10 seconds. For such a well-polished game, it feels like a crime to me! If you had something that let the players react to the attacks in a defensive way and made runs much longer, I think that would create a more compelling experience.