The World of Limbo is a state of existence between life and death. The ultimate goal is for you to escape LIMBO and be at peace in death by defeating Ozai/Skyheed. The world is filled with hazards, including traps, creatures (most notably Koh The Face Stealer), and other, much more hostile humans. Other details of this monochromatic world are absent.
Every obstacle in the Limbo represents a fear of the yourself. As you progresses, you face your fears of, being powerless, heights, and finally, death. He finds his sister burying his body. However, he overcomes it all and reunites himself with his sister, in heaven.
Walkthrough
Proceed forth toward the edge of the tree branch, and drop yourself down the cliff where the inclined slope safely lets you slide down. Beware of the deadly obstacle: jump over the spiky hole to avoid impaling yourself.
Pull the wooden cart until it stops when it is shortly tied by a rope. Climb up until you stand on the top ledge. Jump and grab the rope, but do not fall down too high or you will die. Climb down and you will land safely on the scaffold. You may jump down at the right side better than left one because there is a bottomless pit below the scaffold. When you see the boat, enter it and its chain will be released and you may drift across the lake. Try not to jump yourself on the water, or you will be drowned. Wait for the navigation until you reach the other side of the lake.
At the other side of the lake, you cannot reach the ledge at the end. To get on top of it, pull the boat from the water and step upward to get on the ledge. Climb on the vine, and jump to the hanging chain. Climb up to get to the higher slope. Proceed to the forest, but do not step on one of two bear traps ahead, or you will lose your head. Pull its handle to give wider space between two deadly traps, and jump over them to pass. You will notice a rotten corpse on the rope tied on the cliff branch, but you cannot reach the top cliff when the corpse adds weight to the rope level and branch. To remove it, use the bear trap below. Pull it out and let it aim under the corpse. Grab the rope and the corpse will be obliterated into pieces and lightens the weight.