Ico's nightmare began on the day he drew his first breath. At the moment when he was raised up to the light, a scream rang out into the night. For there, in plain view, was the Sign - two horns, quite small but quite distinct, protruding from either side of the newborn infant's head.
There was no joyous celebration of Ico's birth, no proud expression in his father's eyes. His arrival brought only suspicion and fear. The villagers had hoped against hope that the curse might skip their generation. But here was the Sign, and it could not be ignored. Nor could the plaugues that struck their children, or the failure of the harvests year after year. They prayed desperately for the day when the tribulations would end.
That day, as tradition decreed, was the day of Ico's twelfth birthday. At dawn, the faceless horsemen came for Ico. His family did not try to resist, nor did they weep for the loss of thier child. Ico's fate had been decided long ago.
The horsemen rode deep into the dark twisting forest. Although Ico did not know what his final destination was to be, he could feel his fear rising with every moment that passed. After many hours, an ancient fortress came into view. It stodd vast and foreboding against the stormy horizon. Ico could hear the sound of waves crashing against the rocky cliffs below. His heart began to pound in his chest as he searched desperatly for a way to escape, but found none. His time had come.
Ignoring his desperate cries, the horsemen dragged the terrified boy through the fortress gates and into a vast stone hall. Its walls were filled from floor to ceiling with rows of strange stone caskets. It was at that moment that Ico realised what his fate was to be. The horsemen bundled him into a casket and pulled the heavy stone lid closed, shutting out the light forever. Ico was left alone in the darkness, sentenced to spend the rest of eternity in silent torment.
But now, fate has granted a reprieve. Ico will discover that he is not alone in this mysterious place. A young girl named Yorda has been help captive in the fortress, consumed by lonleliness and sorrow. With Ico's encouragement, she will begin to have hope once more.
However, they will quickly discover that the entire castle is a prison, a fortress from which escape will not be easy. Shadowy spirits emerge from gloomy corners, desperate to drag Yorda back into the darkness. Every twisting staircase, creaking door and towering pillar is part of a larger puzzle. Each torch and shaft of light only serves to illuminate another mystery.
But together, if the pair persevere, they will surely find a way out, a way back to the light...
These scampering creatures will congregate around Yorda, but will not attempt to capture her. However, if you defeat a larger spirit that is nearby, they may morph into a replacement and launch an attack.
Sentries attack with their flightless wings. They will often try to separate you and Yorda before picking her up and walking into a portal. Sentries are difficult to defeat as they can create protective shields around themselves.
These huge hulking spirits have the power to knock you across a room. They sometimes attack in pairs with such violence that you will find it impossible to counterattack. One of their main tactics is to back you into a corner so that you cannot protect Yorda.
The sentinels are a pair of fierce and deadly apparitions. If they manage to capture Yorda, they will use their powerful wings to fly her out of your reach.
Text taken from Ico instruction manual