Stage 12 may appear to be a very short stage, but players who don't take the time to explore it thoroughly will end up missing one of the most important aspects of the game, and it's exceptionally well hidden. An invisible chest contains a Sphinx that opens an invisible door, right in the middle of the bed of flames that lines the floor! If you can find it all on your own, consider yourself an exceptional Mighty Bomb Jack player, but if you can't, don't feel bad; many great players have missed this.
There's only one hidden item in this whole stage, and it's the only thing you should be concerned with. Examine the pictures in the gallery below to learn how to find the hidden Sphinx that opens the hidden door in the floor below. Please note that in the American version, the Sphinx is moved exactly one block closer to the left.
Before you go through the door, it is a good idea to make sure you have at least two Mighty Coins before you enter. The more the better, but if you have less than two, you won't be able to complete your objective. Once you make your way through the door, you will find yourself in a considerably large maze. Use the map below to help guide you through it to the most important rooms that you need to visit. You need to collect a Sphinx in order to access your goal in the maze: the second crystal ball room. You've come all this way, now don't miss it!
The highlighted route will take you exactly where you need to go. Your first destination will be the room in the lower right corner where the Sphinx is contained. Once you get there, you need to travel to the far left side of the room, as shown in the pictures on either side. Hidden against the left side are a series of treasure chests. Only when you reveal the last one on the bottom will you be able to obtain the Sphinx that opens the crystal ball room. Once you've collected it, you'll need to return to the room above, and continue to make your way to the next objective.
With the Sphinx in hand, the door to the crystal ball room will open for you. Don't congratulate yourself too quickly though. You still need to obtain the crystal ball and make it out of the maze safely. Use the picture to the left to guide your jumps so that you remove the blocks necessary to access the ball. Even once you do that, you'll need at least two Mighty Coins in order to access the ball beyond the orange treasure chest. If you don't have enough, you'll have to leave, collect more coins, and return. Be sure to watch out for the enemies after you collect the ball. The truth is, you can collect the ball, lose a life and be returned to Stage 12 without having to escape the maze, and you will still be credited with having collected the ball. Time Attack videos have proven this. However, if you wish to stay alive, simply follow the remaining path back to Stage 12, which generally consists of rising up the left hand side of the maze.