World 4 is open as of now!!
Check the last quest in world 3 (Ninja Village) in order to move forward.
Note: Try not to spoil people with the story as you unravel it. Use a spoiler tag so that anyone may be aware of what to expect.
Edit: Is there a way to post enlarged pic? Such as the one i added in my first post with the world 4 launch pic? Thanks.