When I did the math, assuming Level 1 and 2 have 6 scenes and 3~12 have 8... that makes 92 scenes.
Which leaves two more 8-scene levels, EX and SP? Kewl. Can't wait to find out who gets the honor of being in those.
EDIT:Judging from what it says, I'd guess EX is unlocked on Level 1+53 scene clear and SP is unlocked on 3 EX scenes+58 scene clear. That makes sense.