Interesting concept! The sound effect you chose for that constant countdown really fits well with the theme. I crashed the first time I destroyed an enemy, which was a bit odd. I think I also would have liked the shooting to have been introduced at level 4 instead of later, since it feels like those first few levels are sort of tutorial ones - I definitely TRIED shooting the first time there were enemies, and expected to be able to the second time they showed up. I crashed again later on when I was at the level where you first encounter smaller enemies when destroying a couple. Maybe if I managed to get two at one time, or one got destroyed by me and one by the spinning square? Unsure.
Console showed the following error:
Failed to set the 'value' property on 'AudioParam': The provided float value is non-finite.
(Also noticed the death variable as oh no while in the console and that made me chuckle lol). Definitely an creative take on the theme! (Even if I hate the inverse controls, those are my bane haha, but they make sense for the game!)