Double click the green flag Use your mouse to avoid projectiles, click to damage the boss. This boss-fight is incredibly hard since you only have one life to beat it. Given the difficulty, I'll suggest some strategies to make it easier, keep your distance from the boss to make it easier to dodge projectiles. Take your mouse out of the screen to achieve invulnerability, however, you can not damage the boss at this point...
This is a sequel to "Diamond Gear Bossfight" ( https://scratch.mit.edu/projects/500469502/ )