cool game by the way i dont really like a game without sound. the boss fires in such a way that if stand at a certain distance you can kill him without getting hit

It's a pretty cool concept having time specific changes to the game. One thing I would suggest is to have the monster fire a variety of bullet patterns instead of firing in the same direction each time. I was able to easily defeat the monster by just standing in a spot where the bullets miss each time.

You could probably try setting an array that determines the angle of the bullet spread each time the boss fires.
Ex: [90, 30, 60, 20] degrees apart each bullet

I love the games with a story, and yours is one of them! Despite that probably this is work in progress, I was able to defeat the giant monster. Good job!

This is mine! https://itch.io/jam/brackeys-4/rate/724798