The main character in the game "LIMBO" is a small boy (dubbed Limboy by a few fans). There is no known background for him, so it's a mystery.

The nameless boy.

His appearance is also unknown, for during the entire game he is only a silhouette. All that is known is that he had a strong attachment to his sister. He is presumed dead as due to the main screen images of the same treehouse at the end, and two swarms of flies circling two lumps on the ground (possibly meaning that his sister is dead as well). From the outline of the silhouette, we can conclude that he wears a sweater, shoes, and shorts. His age appears to range from 7 to 10 years. The nameless boy can't swim, as seen whenever he goes into deep water, he drowns immediately.