you can use ghosts you get later in the game in earlier missions.. replay the mission from the high scares pumpkin or whatever from the level select screen
Hm.. then it doesn't work in the earlier levels - I've tried using new ghosts (i.e. Harriet) in older levels (through High Scares) - no go. New ghosts don't show up in the ghost selection screen for older levels. Is there something I'm missing?
EDIT: Yeah, it seems I can use a couple different ghosts in previous levels, but they are not all available. Slowdown must have been the case of overheating, because I didn't see any when I turned my fans up Good to know