Bubble Bobble
Developer: Taito Publishers: Taito (JP/EU), Romstar (US) Platform: Arcade (Tokio/Bubble Bobble hardware) Released internationally: August 4, 1986 This game has hidden development-related text. This game has unused graphics. This game has unused items. This game has unused sounds. This game has a prototype article

They're Bubblin' and Bobblin' all over the place.

Early Graphics

Early	Final	Comments
		Four early versions of the enemy "popped" graphics. The early versions are smaller, and most of the enemies have a classic cartoon X for eyes.
		The earlier star rain graphic is solid yellow with a dark outline. While both animations last six frames, the early star uses three duplicate frames.
		This early conch is red, not pink, and is shaped differently. The final version no longer looks like it's melting at the bottom.
		An earlier, animated version of the butterfly item. Other than the extra frame, the two designs are identical. In the prototype, the butterfly was not a bonus item. That explains why it's animated, but doesn't explain what it would have been used for originally.
		All five chests have different, less detailed designs. Four of them are left over from the prototype, where they were used as point items instead of special items. The cyan one was added later in development.

Unused Graphics

	The spikes atop the player's head make getting squished by bubbles a bit difficult, as it turns out. It is indeed possible in theory, however, it is way harder to execute than one would expect.
	Found in the same set as the early popped enemy graphics. These designs don't match up with any enemy in the final game, but the first one resembles the robot heads from Rainbow Islands.
	There's no bonus item worth 1,200 points, but here's a graphic for it nonetheless.
	This 1,000-point graphic is in the same style and graphics bank as the "multiple enemy popped bonus" graphics. Having a graphic for popping just one enemy seems unnecessary and unwarranted, which is likely why it was never used.
	Graphics for score multipliers! Player scores would certainly be inflated if these were actually implemented in the game.
	Player markers. Flashing player markers. Small, flashing player markers.
	Graphics for what look like gates, maybe? These use the game's level palettes, so this is but one color scheme.
	An alternate bubble design. This is probably from an earlier stage of development, as none of the game's palettes fit the design properly.
	Two different baskets, stored with the rest of the special bonus items. What they would have done is a mystery, but they'd probably act like the food items and give points.
	Oddly enough, Bubble Bobble contains a full set of slot machine icons. These aren't used anywhere and there's no palette that fits them. There is a real Bubble Bobble slot machine, but that's neither here nor there.
	Animations that were likely meant to be used after one player got a game over. Look at him, he's got a little purple suit on! That's adorable. These animations are used, however, in the continue prompt of the X68000 port.

Used	Full

Unused Sounds

Three sounds in the game are unused. Sound 2F would later be used in the 1996 DOS version when getting an extra life, and the Plus/Neo ports for WiiWare and the Xbox 360 for various menus.

100,000-Point Bonus

There's a 100,000-point bonus for popping multiple enemies. This would ostensibly be used after popping eight enemies at once, but there's only space in RAM for seven enemies per stage max.

Put the following code in MAME's bublbobl.xml cheat file and activate it to get this bonus. Please note that due to a mistake in the multiple enemy kill table, this won't give 100,000 points, but just 10!

  <cheat desc="100,000 Point Bonus">

    <script state="on">

      <action>maincpu.pb@F677=08</action>

    </script>

  </cheat>

Unused Bubble Drops

Two of the game's end-of-level bubble drops are unused. The graphics for these items were overwritten sometime in development, so they now use the Red Crown / Level 50 Door item graphics.
Put this code in MAME's bublbobl.xml cheat file to make these items drop:

  <cheat desc="Unused Bubble Drops">

    <parameter>

      <item value="0x0A">Red Crown </item>

      <item value="0x19">Brown Door</item>

    </parameter>

    <script state="change">

      <action>maincpu.pb@F464=01</action>

      <action>maincpu.pb@F465=param</action>

    </script>

  </cheat>

Round 100 Placeholder Setup

Round 100 has a full set of enemies in its level data, just in case the game fails to load the Super Drunk boss routine. Put the following code in MAME's bublbobl.xml cheat file to see this setup:

  <cheat desc="Disable Super Drunk">

    <script state="run">

      <action>maincpu.mw@10637=CA80</action>

      <action>maincpu.mw@12854=C080</action>

    </script>

    <script state="off">

      <action>maincpu.mw@10637=CA63</action>

      <action>maincpu.mw@12854=C063</action>

    </script>

  </cheat>

Build Dates

Game Version

A version string can be found on all variants of the game. This is stored on the main CPU at 0x1FF4C.

MCU Build Date

A second build date (and what is presumably the internal name for the Motorola MC6801U4 Microcontrollers) is stored at the end of the MCU at FFDF. Unlike the game version, this is identical for all versions of the game.

BR10 29.JUN,1986

This is what the "BR10" text on Round 59 refers to. So that's one mystery solved.