General comments:

Visiting the Labyrinth can be decidedly frustrating until you learn its secret. While the level changes every time you visit there is always a ladder in each of the four corners (see map).

There is also a Violet Crystal at the centre. Not easy to find but an important item as you'll discover later. It's also worth two points.

To further complicate matters the level contains numerous floating Spheres. Let them get to close and the experience can be electrifying. They move fast and have a habit of sneaking up behind you. While they don't do much damage they are persistent and a group of them can whittle down you health points in no time. You might be lucky and find a safe spot to rest but don't rely on it.

The Official Hint Book offers a useful tip for minimizing the damage an Electrical Sphere will do when it attacks you from behind:

When a Sphere attacks you from behind, turn halfway towards the Sphere, then use the "look" function (shift + turn key) to instantaneously turn the rest of the way ("looking" left 90 degrees is a lot faster than turning left 90 degrees).

Items to find:

Violet Crystal (two points)

Points to note:

When you pick up the Violet Crystal your total points will increase to 25 which in turn increases your health from 16 to 18.

When you come down from "Beware of Low-Flying Nightmares" you are in the top right-hand corner of the map. The top left-hand corner contains the ladder going down to "Happy Happy, Carnage Carnage". The bottom right-hand corner ladder goes down to "Lasciate Ogne Speranza, Voi Ch'Intrate", while the remaining ladder takes you down to "Need a Light?". Which ladder should you take? Take the wrong one and you could be in for some serious backtracking.

Monsters to kill:

Electrical Spheres

Decision to make:

You see a crystal ladder going down. Descending to Need A Light?
You see a crystal ladder going down. Descending to Lasciate Ogne Speranza, Voi Ch'Intrate.