Mysterium Cheats (GameBoy)

Call up the Map, then press B, Select and Down simultaneously. This allows you to drop
down a level from the level you are currently on.

Lose all your lives and continue, then take the Iron and drop it in the Pool of Fire to
get the Glass Key. Go down the passage and use the key to open the door. Continue down
the passage to find the Vitriolk. Pick it up and use it to be warped back to where you
were before you were defeated.

Call up the Map, then press A, B, Left and Start simultaneously. When you check your
inventory, you will have an item called the "Pass Key" which can open any door in the
game. Drop it into a pool, and it will transform into a "Downlevl" which will allow you
to drop down a level in the dungeon. Drop the "Downlevl" into a pool, and it will
transform into an "Uplevel" which will allow you to transport up a level in the dungeon.
Drop the "Uplevel" into a pool, and it will transform into a "Superpow" which makes you
invincible to enemy fire.

Call up the Map, then press B, Up and Select simultaneously.