Castle of Dr. Brain

The object of the game is to successfully navigate the puzzles Dr. Brain has set up in order to become the mad scientist's assistant (a position Dr. Brain had advertised in the local classified section). To enter the castle, the player must play a game of memory at the front gate. Inside, the player must solve puzzles within the hallways and rooms of the castle. There are also three mazes in which the player must guide an elevator between and among different floors.

Many of the puzzles require skill in mathematics and logic, but the game requires knowledge in a broad range of subjects. One puzzle requires the player to solve a cryptogram, and the penultimate level deals primarily with astronomy. In a rather surreal level, the player must put together a jigsaw puzzle which, when completed, becomes a room through which the player passes to go to the next level.

The Castle of Dr. Brain featured a point-and-click mode of gameplay and three levels of difficulty, which the player could change at any time. The player could also change the pointer from a hand, which would interact with puzzles, to an eye, which would give information about an object (occasionally leading to clues to help solve puzzles). Typically, pointing the hand or the eye at an object that wasn't a puzzle would give a joke about it. The game also featured Hint Coins, which the player earned by solving puzzles and could use for assistance on puzzles they were having difficulty with.