Castle
Original title: The Castle
Platform: MSX
Region: Japan
Media: Cartridge
Controller: Keyboard
Genre: Adventure > Action > Side-Scrolling 
Gametype: Undefined
Release Year: 1985
Developer: ASCII
Publisher: ASCII
Players: 1
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In the puzzle and platform game The Castle you control a prince that has to save the princess. 
To find your princess you explore the castle, which has 100 different rooms. Each room is a puzzle on its own as you have to avoid enemy knights, fat Tiroler men, hazardous objects and have to use objects to get to the next door.
In each room you have to collect keys and items like rings, gold bars and bottles. The bottles will give you an additional life.
The keys may have different colors and only opens doors with the corresponding key color.

As The Castle is a huge game it contains a save and load option. Your current position can be saved by pressing F4.
 
http://www.mobygames.com/game/msx/castle