Castlequest (known in Japan as Castle Excellent (キャッスルエクセレント)) is an adventure/puzzle-hybrid video game. It was developed and published by ASCII Corporation in 1986 for the Family Computer console and MSX computers, and was subsequently released in 1989 for the NES in the United States by Nexoft Corporation.
It is the sequel to The Castle, released in 1985 for the MSX, Sega SG-1000, and other systems (though not the Family Computer or NES).
The object of the game is to navigate through Groken Castle to rescue Princess Margarita. The player can push certain objects throughout the game to accomplish progress. In some rooms, the prince can only advance to the next room by aligning cement blocks, Honey Jars, Candle Cakes, and Elevator Controlling Block. In some rooms, this can be quite time consuming since the prince can only open a particular door if he can stand by the door. Meaning that he can not open the door while jumping in mid-air. The prince must also carry a key that matches the color of the door he intends to be open. The player can navigate the castle with the help of a map that can be obtained from the first room that he/she begins. The map will provide the player with a matrix of 10x10 rooms and will highlight the room in which the princess is located. The player must also avoid touching enemies like Knights, Bishops, Wizards, Fire Spirits, Attack Cats and Phantom Flowers.
Source: Wikipedia, "Castlequest", available under the CC-BY-SA License.