Castle Excellent

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 brick blocks, barrels, Candles, 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 cannot open the door while in mid-jump.

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 found in the first room. 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, Vikings and Phantom Flowers.

Reviewing the Famicom port, the reviewers in Biweekly Famicom Tsūshin commented that the port on the Famicom about as high quality as the port of Lode Runner while other reviewers complimented the cute character designs and lamented the games difficulty. Gary Meredith of Game Players felt that despite starting with 50 lives, the lack of a save feature could make completing the NES version in one sitting frustrating and difficult. "Still, Castlequest is a fascinating game," he said. "Especially for those tired of shooting or slashing their way through the more action-oriented adventures."

Nintendo Power stated, "The action is slow, but the challenge in logic is among the greatest we've seen." The magazine also noted the lack of a continue feature, but said the room reset function in the sub-command menu was helpful.