Finders Keepers is really impressive value. It features graphics reminiscent of Software Projects' offerings, in a format which is almost a combination of Jet Set Willy and Manic Miner.
You are Magic Knight, a nicely animated little character, seeking to join the Polygon Table of the King of Isbisima. In order to please the king, who's run out of ideas for presents for his daughter's birthday, you dash around the Castle of Spriteland visiting various rooms, collecting objects, trading with traders, and avoiding nasties, which all appear in a form which would not disgrace Matthew Smith.
Just so you can be evil and devious, you can either opt for giving the goodies to the King, thus making your knighthood secure, or you can trade all the treasures you find for money, then seek to escape quick before the King gets you!
The program is complete with every imaginable joystick protocol, though some help is needed from the keyboard, and has detailed screen instructions. Not original, but a high quality treatment of some well-loved concepts at a keen price.