"Procedurally generated" usually means the sort of game you can walk through in a weekend but replay as often as you like. The real question, to me, is not how many mathematical permutations are possible when combining the interlocking map/terrain/mission modules - it's how many of these discrete modules are available, how "different" does each map look. Does the virtual landscape actually look different each time, or is it just another psuedorandom jumble of the same dozen terrain components. If there's not enough discrete artwork parts it all starts to look the same, sure the map is "unique" and you'll never see it again, but you'll always know where you are and where to go and you'll start ignoring features which aren't constant landmarks.

Once you've finished the game it becomes more about endgame chores - finding/earning upgrades, improving scores, collecting medals, exploring interesting (but unimportant) bits of the scenery you didn't admire very much the first time through. To me, this is where I begin to really notice the actual quality of the game, I can appreciate the extra dev effort and loving touches, I can condemn all the rushed or lazy programming shortcuts. I haven't played this one at all but at a glance it looks unimpressive - too much effort trying to hype and embellish things that (if they are indeed as truly cool as promised) are better demonstrated through video clips.