Haunted Castle takes place in a medieval castle haunted by a variety of curious and witty spirits. Players are trapped inside the castle and the only escape is through a series of rooms and hidden passageways. Each room has a time challenge which players must solve to get a key to the next room and the next challenge. Once they have collected four keys, they face the final challenge in the tower. The challenges and the rooms are randomly generated, so it's never the same game twice. The castle's ghostly hosts give the game its unique personality and guide players through each room, pointing out possible traps and encouraging during difficult tasks.
Haunted Castle was the first of it's kind for broadcast games channel Challenge TV and it quickly became the most popular part of their web site. The game ran for over two years and was frequently updated.