Guys look i won

same as 2sheep that if he can move while the selection mode, its extremely frustrating, got him and my 2nd attempt but there was indeed some attacks that were very rng in nature like the ghost copies and the laser beam. the other one i've seen looked rather fair however (the bullet hell ones, the chase and the heatseeker missile type bullets. a good amount of variety however ! only if you added frames to anticipate the attacks, it would be more fair. also, unsure what caused that but i beat him while he had 23 hp. maybe it doesn't go to 0 on death ? the theme was a bit mundane in its use, but outside of that it feels it was a good exercice at boss behaviour pattern. hopefully itll help you in future projects ! :)

The game being a one-on-one fight against an enemy who also uses random powers is very unique and interesting.

The red lasers are a bit unfair as they insta-damage you without indication on when or where they appear.

The hard difficulty is ok if there's a pattern to be learned on how to manage the boss. I did not manage to beat him, I guess I should git gud.

I couldn't tell if I was hurting half face, but I know he was whooping me. It's kind of hard. 

Really cool game.  I agree with the others, some kind of indicator is important.  It makes it feel fair to the player.  If you still want to keep a high level of difficulty you can always make the indicator short.  Or make a zone indicator, so the player still doesn't know exactly where it's going to hit but has a chance to dodge.  Overall I enjoyed it and all the elements made it very creepy.

Nice interesting game. Played it a couple of times and managed to defeat the boss twice.

Would suggest that the boss would stop while selecting, I died a couple of times because he moved on top of me while in selection mode.
The red laser beam could use some kind of indication of where it is going to come from, so you have a chance to avoid it.
Good job on the game tough, love all the different abilities the boss has.