"To open the secret portal on level 4, you need to do the following:
At the beginning of level 1, where the starting portal is located, there are 4 objects with a beam falling on them, two on the right and two on the left. You must step on the objects in the following order: Northeast, Southeast, Northwest, and Southwest (Secret code: "3412").Then, you should enter the starting portal of the game. A sound will be played, it can play two sounds, one for error and one for when you get it right, but identifying which is which is easy and intuitive.
If you get the order wrong, you just have to redo it because it resets the string in the map's code when there is an error, allowing you to redo the code (yes, I looked at the map's source code using JassCraft to see how it worked and find the exact coordinates).
Then, you just need to go to the secret area of levels 4 and 7 and step on the "buttons" to open the portals until you reach the portal to the true ending.
And that's it."