Ok, I will try my best. I played on the windows pc 10 on the firefox browser. I opened full screen and played once and killed by boss. Started again and take right upgrade get hit, get second upgrade after some time get hit so shot with basic bullet. I only shot into head and after x shoots one of the bullet stop on the head and game stuck, music played but game stopped. I waited maybe one minute, but nothing happened. Also, when I shot the last bullet, there were no boss bullets, but you can check like that scenario:
- You and boss were killed in the same time.
- Boss is in the "rest" stage when he dies
- Boss started special head attack/ special hand attack when he dies
I forgot One thing can be important, I all time hold space to shoot.