Spore Spawn -A venus fly-trap that was engineered by the Space Pirates.It has a hard shell around the soft core of the mouth, that is the weak point of this abomanation.Once he is out of the way, well another boss will come along.
Kraid -The King of Brinstar, well maybe not because he is one of the dumbest bosses in the game, all he does is roars and open his mouth, so you can shoot him.His projectiles are easilly avoided and you get a nice prize for beating him.
Croccomire -The mini-boss of Norfair, or as I like to call him, the Assistant Manager of Norfair.He is quite formidable if you are not prepared for the fight.He is fast charging, if you dont kill him quickly, he will throw you into a wall of spikes.If you kill him you are treated to one of the coolest boss death scenes ever.
Phantoon This is the ghost gaurdian of the wrecked ship.This guy can get really mean really fast.The more you kill him the faster he his and the more projectiles he will emit.He will fade in and out of view when he is about to die.
Draygon -Now,this guy can be easy or he can keep you in a single point in the game for quite awhile.There is a secret way to kill him, it is on the site.This thing has a hard shell all over his body, but has a soft underside.He is fast and very very very dangerous, so watch out!
Ridley -This guy is by far the hardest, most dangerous dude in the universe.He is fast, powerful, and is very tough.his fire balls due a great amount of damage, his tail whip will lay the smack down upon your metallic butt.He is very diffrent from his first apearance.Keep moving at all costs.
Mother Brain -She is actullay kinda easy, just doge attacks until she fire the "hyper beam" and the hatchling comes to save you, once you get the power, show no mercy.