The Blue Crystal Rod

The fourth and (canonically) final game in the Tower of Druaga/Babylonian Castle Saga series, The Blue Crystal Rod completely abandons the cryptic action game format in favor of becoming a cryptic adventure game, whose big selling point was its 48 somewhat-unique endings. Having finally conquered the Tower of Druaga after three games, Gil and Ki must now restore peace to the world by returning the stolen Blue Crystal Rod to heaven. The outcome of their quest can be anything from a fairy tale happily-ever-after to the apocalypse...assuming they can first overcome the insidious hidden stat checks that bar their way.

Debug Mode#

Turn on the console while holding Left + A + B + L + R + Select on controller 2 (or set RAM $3E to a nonzero value) to activate a debug overlay during gameplay. It shows various key values:

• Top-left: ID of most recently played music track (RAM $B9).
• Middle-left: The index number of the most recently printed string within the current string table (RAM $27).
• Top-right: ID number of the currently displayed graphic (RAM $60-$61).
• Middle-right (labeled SIT, probably short for "situation"): A variable which corresponds to the player's current route and progress in the story (RAM $02F8).
• Bottom: Gil's normally-hidden stats (left to right: power, wisdom, luck, justice, heart, will, love, and experience). These correspond to the values of RAM $02F0-$02F7.

Unused Graphics#

Graphic $004B is a placeholder image styled after signage at Japanese construction sites:

"Naito" refers to programmer Satoshi Naito.

Graphic $011B is a duplicate of this image with an incorrect palette.

Unused Text#

Knight

This string is used to check if the save RAM has been initialized or not. It's once again a reference to programmer Satoshi "Knight" Naito, who used the same text for similar purposes in other games he worked on, such as Family Circuit '91.

ここはどこでしょう？

The game normally displays the current area name at the top of the screen. Area name $00 is this unused placeholder.

ハーサグ「あなたの行動は、バグのも
　たらしたもの…。
　　この世の物ではありません。」

An error message displayed in Harthag's fortune-telling house if the game is in a state with no corresponding fortune message.

村長「アルゴリズムに、バグが存在し
　ます。
　　リセットしてやり直すか、レポート
　を提出して下さい。」

The elder of Narak Village normally gives the player contextual advice based on their current route. As above, this error message would be used for situations with no programmed response.

イシター「カイよ。
　　失った物を思うより、これからの
　事が大事です。
　　ギルの分まで、あなたが、がんば
　るんですよ。

Ishtar would provide this guidance if she was visited with a SIT variable of $34. This corresponds to the end of the ENWS route, where Gil is killed by Anshar. It's impossible to visit Ishtar under this circumstance because the game immediately proceeds to the ending once Gil is dead, and the player never has the chance to return to Babylim. There may have originally been plans to have the player finish out the game as Ki.

This is not considered a "valid" state for fortune-telling purposes, and visiting Harthag for a reading afterward will result in the "your actions have caused a bug" message.

イシター「ギルガメス！
　　もはやあなたと私では、住む世界
　が異なります。
　　出て行きなさい。」

This Ishtar message doesn't appear for any value of SIT. It was most likely intended to correspond to $3F, the NWSE "worst ending" (where Gil is corrupted by Anshar and Nergal and becomes the next Druaga), but this isn't programmed correctly and results in nonsense instead. There is no opportunity to visit Ishtar on that route because the game ends as soon as Gil talks to Garru.

This is notably the only time in the entire script that Ishtar refers to Gil by his full name of "Gilgamesh."

Save Delete Menu#

The game contains an undocumented feature for deleting save data: while in the options menu, press Select to open the menu shown above. The options are as follows:

• A: Delete the save file currently highlighted by the cursor.
• B: Delete all save files (immediately, with no confirmation!).
• Y: Return to the options menu.

This feature isn't listed in the game's manual. Considering it's very easy to accidentally wipe all the save data while trying to leave the menu, perhaps that's for the best.

Regional Lockout#

If run on a PAL console, the game will display this error message and lock up after Start is pressed on the title screen.