Hi, I'm playing Amazing Spiderman on the PC, and supposedly the negative zone costume unlocks after you complete all the Xtreme challenges... which I just did. I got the steam achievements for completing them all, but no costume was unlocked for it. How do I get the negative zone costume on Steam then?
the negative zone suit didn't unlock for me until i completed every side-mission on the map.
however, that may not have been the specific requirement. the last set of missions i did before unlocking the suit was car chases, so perhaps you need to complete all of those to unlock it. if that doesn't work, then just complete all the other side-missions until you get it.