Talk:General Discussion/@comment-114.160.71.148-20140720200305/@comment-93.55.160.11-20140720210547

As in normal sortie maps, to unlock world 5 you first need to complete world 3 and 4.

But you can start from whichever you prefer ( world 3 or world 4 ). So it's being speculated that we'll have two open maps instead of just one. And we need to complete both to unlock the remaining.