Mage: The Enchanted Crystals (Chroma colour) (longplay) for the ZX81

Came also out for:
Commodore PET/CBM
Odyssey 2
Videopac+ G7400
Game description:
Mage: The Enchanted Crystals the second game to feature Wizzy, the main character of Mayhem. The Wizard of Odyssey, Wizzy's father, was working on a powerful spell, but was being watched by others. To protect the spell, he captured the spell inside a crystal and divided it in 4 pieces, hiding them in the mines just south of his village. Now it is up to Wizzy to collect the crystal pieces and place them inside the enchanted chest.
The gameplay consists in wandering around the mines while avoiding the monsters inside it. The mines are a big maze divided in several screens, in a way similar to Atari 2600's Adventure. Some areas of the mine are locked and the player must search for the appropriate keys. The game must be finished within a fixed time limit.
The game features internet highscore uploading and an online rewards system. To upload the highscore, players receive a code upon finishing the game, which must be entered at the developer's website. The online rewards work the same way, and there are four of them:
[bronze] Finally! - Finish the game
[silver] Close call - Finish the game with less than 1 minute to spare
[gold] Mazerunner - Finish the game in 5 minutes or less