For some reason, despite people saying that Kraid, (the boss of Brinstar) is easy in Super Metroid, I had A LOT of trouble when fighting him. First of all, he has a lot of intimidation factor, Being even bigger than the FINAL BOSS! His weak point is his eyes and his mouth, which makes you have to climb off platforms, but falling from them (which you will, a lot) will net you some serious damage when you fall onto the spikes. His grunts and roars, as well as his battle theme, also increases his intimidation. Fortunately, beating him will get you the Varia suit, which lets you go into planet Zebes's core, Norfair.