The black hole is defeatable, you just have to spam dash away from it, I will admit 2 black holes are a bit too much, after the jam I'll make sure there's only 1 blackhole. Missile launcher and flamethrower are indeed buggy, I tried to solve it but couldn't under the game jam timeframe so sorry for that. As for the spearhead, I thought about adding a charge up animation, but that would have made it too easy imo. And many bosses have programmed to avoid bullets to the best of their ability. You have to either trap them, have multiple bullets upgrade, or have speedy bullets.