Ico is an action-adventure video game designed and directed by Fumito Ueda who wanted to create a minimalist game around a "boy meets girl" concept. Originally planned for the PlayStation, Ico took approximately four years to develop. The team employed a "subtracting design" approach to reduce elements of gameplay that interfered with the game's setting and story in order to create a high level of immersion.
The titular protagonist is a young boy, born with horns his village considers him a bad omen. Warriors lock Ico away in an abandoned fortress and during his explorations Ico encounters Yorda, the daughter of the castle's Queen. Ico seeks to escape the castle with Yorda, keeping her safe from the shadow-like creatures that attempt to draw her back. Throughout the game the player controls Ico as he explores the castle, solves puzzles, and assists the less-agile Yorda across obstacles.
Ico introduced several design and technical elements, including a story told with minimal dialog, bloom lighting and key frame animation, that have influenced subsequent games. Though not a commercial success it was critically acclaimed for its art and story elements and received several awards including "Game of the Year" nominations and three Game Developers Choice Awards. Ico is listed on several overall top game lists, and is often considered a form of art. The game was reprinted in Europe in 2006 in conjunction with the release of Shadow of the Colossus, the spiritual successor to Ico.
Source: Wikipedia, "Ico," available under the CC-BY-SA License.