Before starting the explanation for which I got this achievement, is better to say immediately that is totally different from the way I got it compared to the various methods already described by other players. After several tests, I have the certainty that one must have a very lucky run, as regards the random procedural creation of the levels. I am sure of what I say because many tests described by others actually don't work, this instead worked, although it appeared in an unexpected way (in the explanation you will understand this statement).

I was on the first level, the usual first level but with many outdoor areas and large terraces.
I see the exit in the distance, to get to the end of the level, I find myself in these open spaces, the walls of the buildings are completely destroyed and a maze of terraces connected by stairways.
The last staircase leads to a terrace with one of those large crystals, those that serve to call the lifts or to rotate the bridges, in this case both things; there was a large bridge that was lifted, when arriving at the aforementioned crystal the bridge is lowered and next to it two small platforms and many rocks floating around them. If I had called him back, the bridge would go up and I could reach the door that brings me into the level elevator room.
What I did, was this:

• I left the bridge in the lowered position.
  
• I didn't go to open the pay door for the last room (so the door was closed).
  
• I descend on the bridge in the lowered position, I realize I'm in a favorable position (I am already about halfway between the first and second levels but if I jumped it triggered the fall teleport).
  
• I look at the floating stones and I see that some would allow me to get to the second level without triggering that boring teleport.
  
• I descend carefully to the second level using the rocks, just in front of the sentient pyramid and I don't get the achievement (OK there can stand, I had already made similar attempts without getting anything but in this case it was different).
  
• Once I got to the second level I notice that in fact I have absolutely not used the elevator (I don't know if this can affect) but the hole where it fits the platform was open (it's normal the platform had remained at the first level); from it I could see under the third level (the swamps) with their rock formations, and one made mushroom type was right below the hole, not too deep.
  
• I don't open the start door of the second level (I don't know if this can affect) and jump from the platform hole to reach the third level.
  
• I fall on that rock formation that was near them, without activating the teleport and I get the famous achievement.

Curious detail: after obtaining the achievement since I was still high enough, I try to reach the ground floor of the third level, I throw myself and just touch the ground, I die despite I still have a lot of life and the teleport from fall has not activated (cursed teleport when needed does not activate).
I hope to have been exhaustive in the explanation and good hunting.


In the upper right the activated crystal, at the center the bridge in the lowered position, at the bottom left the floating stones with below the second level.