A Haunting by the Shadow - Quick gameplay explanation

About A Haunting by the Shadow, from BoardGameGeek:

A Haunting by the Shadow is a cooperative game in which 2-4 players investigate a house overrun by dark and sinister spirits. The spirits are led by a greater evil known as the Shadow. Players must discover items within the house to help them eliminate the ominous spirits. But time is against them. With each passing moment, the Shadow's power grows. If the players take too long in their search, the spirits could unleash an untold terror into the world. Players will take actions to move, search, or vanquish spirits that are haunting the Harris House. Players will gather items that will allow them to vanquish the spirits. Before the players get the items, they must avoid interacting with the spirits and must avoid the Shadow at all costs. If the players vanquish the 4 spirits, the players collectively win and the Shadow is defeated. -description from designer