There are eight floors in the tower that you must invade. Each floor is connected to the floor above and the floor below. With the exception of floors 4 and 5, there is only one staircase between each floor. You begin the game on Floor 1 (the outdoors), and must make your way to Floor 8 by traversing each floor to find the staircase that leads to the next level. There is no way to skip any floors, but you may also travel back down to floors that you've already visited.
To complete the game, you must reach the eighth floor and destroy the demon prince skull that blocks the final staircase by casting a Chaos spell. You are then given a rating based on your performance. Your rating is determined by the following criteria:
- Your rating increases the more enemies you kill.
- Your rating increases a lot for each demon prince skull you defeat (there are four in total).
- Your rating decreases the more you open treasure chests.
In order to get the best rating, you should attempt to kill as many enemies as possible, including all four demon prince skulls, and open as few treasure chests as you can afford to. However, it should be noted that you can open all of the treasure chests and still get the best rating, provided you kill enough enemies to compensate for the penalty.
Changes in the Famicom Disk System version
- The Destroy meter
- Instead of displaying your rating as it accumulates throughout the game, you are instead shown a Destroy meter. The meter has ten bubbles which are red when half full, and blue when full. You fill half of a bubble for killing each enemy. When twenty enemies are killed, the meter will be full. At that time, the meter will empty and your druid will gain a small boost in health.
- Treasure items
- In addition to obtaining spells from the treasure chests, you can also obtain Template:~. Some items are helpful, while others weaken you. In general, items that are helpful lower your rating at the end of the game, while possession of harmful items raise your rating. Like spells, you can only choose one item if a chest has more than one to offer.
- Demon prince skull locations
- The original game places all four skulls on the last four floors of the game. The FDS version moves the skull from Floor 6 to Floor 3, spreading the skull appearances out more evenly throughout the floors. They now appear on Floors 3, 5, 7, and 8. The 5th, 7th, and 8th floor skulls are in the same locations as in the original. The 3rd floor skull appears right next to the staircase to Floor 4.
- Wraiths as an enemy
- In the original game, wraiths are simply a basic enemy which appears and attacks like many others. In the FDS version, wraiths only appear if you remain in one place for too long. They harm you by merely appearing somewhere on the screen, before blinking out and appearing somewhere else.
- Final boss
- After the demon prince skull on the eighth floor is destroyed, and you travel through the staircase, there is a long battle against a final boss which has two phases. The boss must be defeated in order to see the ending and receive your rating. Depending on your rating, one of three different ending scenes will be shown.