Bubble Bobble

Bubble Bobble is an arcade game by Taito, first released in 1986. It features two cute dragons, Bub (Japanese "Bubblun"), who is green with yellow spikes and Bob (Japanese "Bobblun"), who is blue with cyan spikes. They move over a system of platforms, busting and pushing bubbles, avoiding bad guys and collecting a variety of power-ups.

Game mechanics
The original arcade game, despite its release date (1986) and its apparent simplicity, features some rather complicated and convoluted game mechanics, one of the main reasons that most computer or game console ports of the game, even when released several years after the original, seem lacking and incomplete in many aspects.

Levels
Each level (or round) consists of exactly one screen, with no scrolling or flipping. The dragons can move around the levels by walking on platforms, falling through empty space, jumping through platforms from below and (in some levels) falling through holes at the bottom of the level in order to reappear at the top, or even vice versa (see gameplay techniques below).

Apart from jumping, the characters can blow bubbles. Bubbles also float in from the top or bottom of the screen in many levels. They pop after a certain amount of time, when they hit the dragon's spiked back, if they're squashed against a wall or another dragon or if they're fallen upon. By holding down the jump button, it's possible to bounce on top of bubbles, which is sometimes necessary to reach platforms. The main objective of the game is to trap enemies in bubbles, then burst the bubble, thus destroying the enemy.

Each round also features invisible air currents and custom bubble physics, causing all bubbles to move in predetermined trajectories like converging to a certain point, moving very quickly or very slowly, rising too fast, being pulled down as if by gravity, etc., usually with notable effects on a level's difficulty.

Some levels have very short bubble popping times, meaning that bubbles pop almost as soon as they emerge. This is extreme to the point of only being able to kill monsters by "kissing" them in later levels - which means blowing a bubble in such a way that it's immediately squashed against the dragon (possibly by faulty game mechanics) causing instant death to an enemy. Very short time limits are also used to make the game more difficult, with two rounds having no time limits and a few of them being almost impossible to finish under certain conditions (single player, lack of certain bonuses etc.). It's important to note that when you run out of time, you do not instantly die, but rather an invincible "Skel" enemy appears (two if there are two dragons playing) - for more information on the Skel enemy, see below.

Enemies
There are a variety of enemies that move about in different patterns. Contact with an enemy (or the missiles fired by some) will kill a dragon. The dragons' job is to complete the level by killing all enemies in it. If this is not achieved within a time limit, the message "Hurry up!" will flash across the screen. When this happens, enemies become "angry" (making them move faster thus making them more dangerous). Approximately ten seconds later, one or two Skel enemies appear on screen. Enemies also become "angry" if they escape from a bubble that is not burst quickly enough by one of the dragons. They calm down when one of the dragons dies.

There are 7 kinds of normal enemies, plus the final boss and two kinds of invincible monsters that appear after the "hurry up" limit, each with their own names. Roughly, in order of appearance, they are:
 * Bubble Buster (Japanese "Zen-Chan"): A box-shaped, clockwork walking monster with a medium moving speed and good jumping abilities. Interestingly, this monster appears in the graphic tiles of the ROM of the arcade game Chack'n Pop, along with the Stoner and Beluga, but doesn't actually appear inside the game.
 * Stoner (Japanese "Mighta"): A walking monster with red eyes wearing a white robe, much like a ghost. Has a medium moving speed, good jumping abilities and able to shoot. This monster actually first appeared in Taito's 1983 game Chack'n Pop.
 * Beluga (Japanese "Monsta"): A flying blue/dark purple monster shaped roughly like a small whale. It flies fast but can only bounce off walls to change direction. This monster also first appeared in Chack'n Pop.
 * Hullabaloon (Japanese "Banebou"): A pink flying monster looking like a toy bear with a small rotor on his head. Flies around slowly but with greater control than the Monsta. Can also creep in very small openings other monsters and players cannot pass through, making it very dangerous in some rounds.
 * Incendo (Japanese "Hidegons", singular): A fast walking monster with shooting abilities, but poor jumping. Unlike the Mighta, he doesn't have to stop walking in order to shoot fireballs.
 * Colley (Japanese "Pulpul"): A mushroom shaped-monster which can only move by making short jumps, having a single powerful spring instead of legs.
 * Willy Whistle (Japanese "Drunk"): A fast moving monster with good jumping capabilites, and able to throw a bottle which rebounds off walls and is re-caught by the thrower. The final boss is modelled after them, but is instead called Grumple Grommit or Super Drunk.
 * Super Socket (Japanese "Invader"): A robotic-looking monster, fast, but can only move left or right. It can shoot, but only vertically (downwards), making it very dangerous in some stages. First appears on stage 60, and doesn't appear at all in the Super version of the game, being replaced by Incendo or Colley instead.
 * Baron von Blubba (Japanese "Skel-Monsta"): It is the invincible monster that appears after the time limit for a round has expired (this limit can be as low as 1 or 2 seconds on some rounds, but there are two rounds with no time limit; round 94 and round 100). It looks like a white Monsta but it can only move vertically or horizontally at timed intervals, but can pass through walls, ceilings, floors and it speeds up each time players avoid getting caught, down to the point of moving continuously. In two players mode, two Skels appear, each one homing on one player only, although both players can be killed by touching either of the Skels. A Skel can only be destroyed by killing a player, or if a player who has just been killed touches his companion's Skel while he is still flickering, and thus invincible. However, he disappears when the last regular enemy is destroyed. Another way to get rid of Skel is to pick up the flashing heart powerup (the only one which remains on the screen after the "hurry up!" warning.
 * A smaller Skel (Japanese "Rascal") also appears in the secret diamaond-filled rounds, which can be accessed by special bonuses that sometimes appear on rounds 20, 30 and 40. Losing one's last life inside such a secret room will cause the maximum round reached to be "Round 102", "Round 103" or "Round 104" depending upon in which secret room death occurred, and the first new game started after that will teleport players to the first secret round straight from round 1, but will also cause secret rounds to appear earlier, at stages 10, 20 and 30, and the special 20-stage skip bonus on stage 40 instead of stage 50.
 * Grumple Grommit or Super Drunk is the endgame boss that appears in level 100. He is huge, bounces off walls, and fires arcs of bottle-shaped missiles. The level contains a magic potion that lets you breathe lightning bubbles, and you have to hit him with lots of lightning to trap him in a bubble. If this bubble is not popped soon enough, he will escape and become angry just like regular enemies.

Weapons and bonuses
The dragons' main weapon is their ability to blow bubbles. After being blown, they shoot forward for a short distance, then float upwards slowly. It is possible to jump on bubbles to reach otherwise inaccessible areas. An enemy hit by a forward-shooting (not floating) bubble will be trapped in it. The bubble can then be popped, killing the enemy and turning it into an item that can be collected for bonus points. If left floating, it will become angry and escape the bubble after a while.

In some levels, there are special bubbles that appear by themselves:
 * Bubbles with letters that yield an extra life when one collects a complete set - all six letters to spell 'extend'. Extend bubbles appear when one has popped several enemies at the same time on the previous level. They will only appear on levels which have holes in the top or bottom of the screen.
 * Water-filled bubbles that can be popped to release a stream of water that flows down and drowns enemies, turning them into 7000-point blue diamonds.
 * Bubbles containing lightning bolts that, when the bubble is popped, shoot sideways (even through walls) and kill any enemies they hit, turning them into 8000-point yellow diamonds. The lightning goes in the opposite direction of the dragon that popped it.
 * Bubbles containing flames that, when the bubble is popped, drop downwards setting any surface they touch on fire for a short time, killing any monsters that touch the flame and turning them into 9000-point red diamonds.
 * A very rare red bubble with a pulsating yellow spark, which when popped awarded 100,000 points and gives the player which popped it the ability to breathe fireballs for the six consecutive rounds.

The main power-ups are:
 * Shoes that enable faster walking and jumping
 * A blue candy which increases the travelling and forming speed of bubbles
 * A purple candy which increases the shooting range of bubbles
 * A yellow candy that increases the rate at which bubbles can be blown.
 * A yellow lamp which gives all three bubble-related bonuses.
 * A red cross which gives the player who takes it the ability to breathe flames until the end of the current round.
 * A yellow cross which causes several lighting bolts to cross the screen, killing any monster they hit, including bubbled ones.
 * A blue cross which kills all monsters by flooding the round with water. This takes some 3 or 4 seconds to complete though, and players are still vulnerable.
 * A red lamp which instantly kills all monsters, turning them into 9000-point red diamonds.
 * A bomb, which instantly kills all monsters, turning them into 10,000-point dark blue diamonds.
 * A book, which triggers an earthquake that kills all monsters.
 * A candy cane that gives large power ups worth varying large amounts of points depending on color

In addition to this Bubble Bobble has several secret levels. These can be accessed by not losing a life before levels 20, 30, 40 and 50. For example, if you complete level 20 without dieing a grey door with flames on either side will appear in the next level. Inside the level is 36 diamonds and a message in a special symbol font. When you complete the game on normal mode the way to decipher the code is explained. The level 50 doesn't take the form of a secret room, but instead is a 20 level skip.

Timer, event and counter triggered bonuses
A relatively unknown and obscure part of Bubble Bobble gameplay has always been the way the various bonuses appear. While most of them may appear completely random, the game actually keeps a series of internal (and unseen) counters about events such as number of jumps, jumps over bubbles, bubble bursts, bubbles blown etc. during a round or in the whole game, maximum number of monsters blown in a certain round etc. and these events are actually used to determine which bonuses will appear, and to a certain extent when they will appear.

Some known events and the effect they have on bonuses are:

The number of distinct EXTEND bubbles that will appear on a round depend on the maximum number of monsters killed during the round, or on a previous round if said previous round didn't have "openings" for EXTEND bubbles to fly in, or was completed before they could appear. In general, killing N+1 monsters will make N distinct EXTEND bubbles appear. Since the game actually can have only 7 monsters per round, killing 7 monsters in a single bubble cluster will make all 6 EXTEND letters appear.

In Taito's PC port, however, killing N monsters will cause the N-th letter of the word to appear - making the N extremely hard to get because there's only few levels where you can easily pop five enemies simultaneously. This is probably a bug.

Another known event-triggered event is the appearance of candy cane bonuses: if a player rides a bubble more than 20 times, then a candy cane will surely appear in that round.

Other bonuses can be made to appear in similar manners, and there are lists of events and effects around the internet.

For a special bonus on the NES version, a player must enter the password HIJID, select 2 player continue, and finish round FO (last level) with both players alive. After the entire ending has run and the player is prompted to press start, the player will receive a reward. The reward is a sound test for the whole game.

Playing techniques and styles
Bubble Bobble is a game heavily relying on gameplay and precise technique rather than graphics, and it features a series of special techniques and tricks a player can perform to maximize his or her score, make some rounds of the game easier or faster to finish or just to be able to survive or even finish a round.

Some of these techniques have special nicknames, which may differ from player to player and from country to country.


 * Kissing monsters or just kissing means killing a monster by blowing a bubble at almost contact distance: the monster will be instantly bubbled and the bubble will be instantly popped, giving the visual effect of the player killing a monster with a "kiss". Some players flip their joysticks in the opposite direction after pressing the bubble buttons, giving more chances of an "instant pop" and changing flight direction for the dead monster. This technique is useful in stages where monsters move too fast, bubbles last for too short of a time or it's otherwise hard to bubble them normally. Of course good timing is required for this technique to work.
 * Riding bubbles means keeping the jump button pressed when dropping on a bubble: if done correctly, instead of popping the bubble, your dragon will instead jump on it, possibly continuously, enabling him to "ride" bubbles in order to reach otherwise unreachable areas. Some stages can't be finished without this technique.
 * Bubbling oneself through means "riding a bubble" through the opening at the top of a stage or even just through the ceiling of a stage in order to appear at the lower part, like some flying monsters can do. This technique is required to finish some stages or to get unstuck from some places, or just to save time.
 * Blowing against the wall means blowing bubbles against wall at contact distance: the bubbles will pop immediately thus giving the player 10 points per bubble pop. This can be used to either increase a player's score, or to set a player's score to a specific amount, in order to do other tricks.
 * Two equal digits means using the "blowing against the wall" technique or other score-adjusting techniques in order to make the two penultimate (100s and 10s places) digits of at least one player equal, e.g., 456770, before the last enemy bubble is burst. If done correctly and the score is not modified when this occurs, then all remaining non-special bubbles on screen will be turned to 700-point bonuses, whose appearance depends on the digit picked. E.g., 7 gives Chocolate Ice Creams, 3 gives Hamburgers, and so on.
 * This trick is easier to do with two players (one player adjusts his score and the other bursts the bubbles), but it can also be done with only one player, although calculating exactly how much (and if) one's score will be modified when bursting the last enemy bubbles can be extremely complex, if not unpredictable, especially if there are very large and clustered bubble bunches.
 * Rounds with numbers ending with 5 and 0 generate bonuses from bubbles automatically, though, and some rounds (including round 1) do it by default.

Ports
The popularity of Bubble Bobble led Taito (or its licensees) to port to many home computers and video game consoles. Ports of the game were released for the Commodore 64, ZX Spectrum, Commodore Amiga, Atari ST, MSX, Amstrad CPC, X68000, PC (MS-DOS, 1989 and 1996), Apple II, Sega Master System, Game Boy, Game Boy Color, Game Boy Advance, Nintendo DS, PlayStation, Sega Saturn, Nintendo Entertainment System, Famicom Disk System, Sega Game Gear, mobile phone (Sprint PCS), and UltraCade's Taito Arcade Classics.

In October 2005, a version was released for the Xbox, PS2, and PC as part of the Taito Legends compilation of retrogames.

Game mechanics in conversions and ports
Bubble Bobble has been widely recognized as one of the most playable games of all time, owing much of its success to its previously described game mechanics, which are only apparently simple, and its many hidden features and secrets. Also, most Bubble Bobble players usually manage to master techniques such as riding bubbles, bubbling oneself through the screen or kissing monsters, and expect them to work all the time.

Some Bubble Bobble ports however, from the date of release of the arcade version up to day, have been heavily criticized for the poor quality of their mechanics (or, rather, their not being similar enough to the arcade).

For example, in many versions of the game the two-digit trick to make extra bonuses appear at the end of the stage just doesn't work, or the score and bonus awarding system is entirely different, in part due to the complexity of the original one, and most of the aforementioned techniques can be much harder or impossible to reproduce, thus completely changing (or even ruining) the gaming experience.

Examples include even comparatively recent versions such as the (1996) PC/Playstation/Sega Saturn version by Acclaim: it had completely wrong game physics (too fast dropping speed, barely working shoes, bubbles going through walls, different jumping physics and many non-implemented techniques) or different (hence, wrong) behaviour for some monsters (especially the time-up monster).

Another example is the early 1989 PC version by Novalogic, which had the possibity of diagonal jumps with a single keystroke, enabling players to go through walls, and lacked completely the ability of kissing monsters.

The various Nintendo NES and Game Boy ports and sequels are very different, often featuring scrolling screens, different enemies, and the ability for the dragons to fly.

In general, there as many variations to the game mechanics as there are versions, with some being better than others and some resulting in one's completely different experience with the game. Although that is a general rule regarding ports of any game, in Bubble Bobble it becomes very noticeable and annoying because of the game relying primarily on its fast paced and trick-filled gameplay.

One of the few versions having game mechanics and gameplay very close to the arcade is the Sega Master System version, despite its introduction of extra gameplay elements. Moreover, the version included in Taito Legends for the Xbox, PS2, and PC should be a near-perfect copy of the original arcade version, as it supportedly features the original ROM running under emulation.

Legacy
Bubble Bobble inspired many sequels, including:
 * Rainbow Islands - The Story of Bubble Bobble 2 (1987)
 * Rainbow Islands Extra Version (1988)
 * Final Bubble Bobble (1988 Sega Master System)
 * Parasol Stars (1991 originally released for NEC PC-Engine, converted for Amiga, Atari ST, Game Boy and Nintendo Entertainment System (Europe))
 * Bubble Bobble Part 2 (1993 Nintendo Famicom, Nintendo Entertainment System, Game Boy)
 * Bubble Bobble II (World) / Bubble Symphony (Europe, Japan, U.S.) (1994 Arcade, Sega Saturn (Japan only))
 * Bubble Memories - The Story of Bubble Bobble III (1995 Arcade)
 * Rainbow Islands - Putty's Party (2000 Bandai Wonderswan)

There are a couple of previous Taito games which sort of anticipated the Bubble Bobble legacy because of their inclusion of characteristic common elements or even monsters (e.g. the Mighta and Monsta both appeared first in the game Chack'n Pop, and in fact level 29 of Bubble Bobble is a direct copy of level 1 of Chack'n Pop) :
 * Chack'n Pop (1983)
 * Fairyland Story (1984)

Bub and Bob also appeared in Puzzle Bobble, otherwise known as Bust a Move in the United States. Bust a Move was followed by many sequels, for many consoles, including PlayStation, Nintendo 64, Game Boy, Game Boy Color, Game Boy Advance, Nintendo GameCube, PlayStation 2, Xbox and even the N-Gage, along with computer and arcade versions. It became more popular than the original Bubble Bobble game itself.

Similar games, spinoffs, and clones
Bubble Bobble's successful gameplay has inspired not only many official sequels and spinoffs by Taito, but also a number of games with very similar gameplay elements. The most important of them include:
 * The non-scrolling platformer action.
 * Dividing the game into many levels (typically above 30).
 * Defeating enemies by trapping them somehow instead of killing them right away.
 * Collecting bonuses and finding secret ways of increasing their value.
 * Collecting letters to gain an extra life.

Some examples of successful non-Taito video games resembling Bubble Bobble in some or even all of the above aspects are:
 * Rodland by Jaleco (1989).
 * Snow Brothers and its sequels by Toaplan (1991).
 * Tumblepop and Diet Go Go by Data East.



Clones
Ultra Balloon (1996), by SunA Corporation (also manufacturer of Hard Head series), is an evident Bubble Memories copy and the only Bubble Bobble-inspired arcade game to actually copy the bubble-blowing and popping system.

Bubble Bobble also inspired a few software publishers to publish derivatives of the game for the PC and Mac. Such titles include Bubble Bobble World, Bubble Bobble Quest, Bubble Bobble Nostalgie, Bub & Bob, and The Bub's Brothers. Such games are marketed online.