Mysterium

Quick Continue

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.

Level Drop

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.

Pass Key Plus

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.

Inventory Overload

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