Use arrow keys to move and dodge black. You will auto-fire up. You have 5 hp, and each time you get hit, you will take 1 damage and have 2 seconds of invincibility. Every time a bullet hits the red, it will take 1 damage. It starts at 400 health, and you must knock it down to 0 to win. You lose if you run out of hp. Press space for hardcore mode (1 hp). Press p for practice (100000 hp, 4000000 boss hp. Just practice without constant dying)
tell me if you find bugs. It definitely is possible (and possible not to take damage), but it is very hard.