you need to defeat venom at the showdown

u have to go 2 dr conners and tell him that his mom married venom then he will be angry and make this video on how 2 become a lizard (u will c it later) and let the lizard (dr conners) go 2 the sewers where he will get married 2 a crocodile and get babies. then swing by his mom and tell her that her son became a lizard and is ddoing it with a crocodile. She will scream and venom is making out with her so the suit goes from venom to u (spiderman)

Beat sanman first, then you are in it.

get to the green goblin level and then beat him and get to the next level.after u beat the greeu goblin press start and the u go to anchievements and it say black suited spider man go to that one and click yes, then u will have the black suit on.
by the way if u are in the black suite u will be much more powerful and u will get passed levels much easier.