Guide for the secret world:
There are hidden switches on every map that need to be activated BEFORE you recruit NPCs. If you screw up, you need to reset the game in the settings
Green world: After collecting the dream catcher, do a leap of faith across right wall to climb an invisible ladder (if you didn't got it, try bit more to the left), then activate the switch on a table outside of map.
Blue world: Jump on the fence surrounding the warehouse, then walk along it towards the blue container behind the warehouse and jump on it to access the switch.
Pink world: Find the grave, go through the passable wall on opposite side, then go through the wall behind dream catcher and keep walking forward. Switch is on one of poles.
Yellow world: After reaching level above the dragon with first magic mirror, you need to jump on two bookshelves to access the platform behind the pillar with the mirror. Then walk along right wall following the bookshelves above until you reach the passable wall
Secret world: There are three buttons you need to press in order to access remaining secrets.
-Turn left after spawning in and head towards the ramp to activate the first bride
-Remaining ones are on other side of the arc. One is hidden on the left where you need to jump onto a small path in upper-left corner. Other is on right side, just find the door on a wall in the distance and look to the left. Don't forget to walk the final stairs, get your reward, and access three doors!