Doki Doki Panic

Yume Kōjō: Doki Doki Panic (lit. "Dream Factory: Heart-Pounding Panic") is a 1987 platform game released for the Famicom Disk System about a family who plans to rescue two children. "Doki doki" is a Japanese onomatopoeia for a rapidly beating heart, and it is commonly found in Japanese video game titles, carrying connotations of excitement and anxiety.

The game is known for its Western conversion in 1988 as Super Mario Bros. 2 for the NES which had its characters changed to those from Nintendo's Super Mario Bros. The western version of Super Mario Bros. 2 was also released in Japan for the Nintendo Famicom as Super Mario USA.

The game was developed in cooperation with Fuji Television to promote its Yume Kōjō '87 (tr. Dream Factory '87) event, which showcased several of Fuji TV's latest TV shows and other products at the time. The game featured the mascots of the Yume Kōjō festival — a family consisting of siblings Imajin and Lina and their parents, Papa and Mama — as its main characters. The rest of the characters, including the main villain, Mamu (known as Wart when localized for Super Mario Bros. 2), were all creations by Nintendo for the game. The game takes place within a book with an Arabian setting. All four characters are playable, and the game is not fully completed until the player plays through as all four.

Even though it was not originally conceived as a Mario game, Shigeru Miyamoto had a larger involvement in this game than he did with the original Super Mario Bros. 2 (known outside Japan as The Lost Levels) which was released in Japan. Some elements from the Mario universe already existed in Doki Doki Panic, such as the Starman, coin and jumping sound effects, the POW blocks and level warping. Also, the game's soundtrack was already composed by Kōji Kondō, the original Super Mario composer, and upon the conversion needed only a few alterations such as removing most of the arabian elements, replacing them with original Super Mario tunes.

In 1988, the game was localized for North America, Europe and Australia as Super Mario Bros. 2. The Yume Kōjō family members were replaced by Mario, Luigi, Princess Toadstool, and Toad, and numerous other small changes were made, such as the B Button on the NES controller making the characters run. Yume Kōjō: Doki Doki Panic represents the original source of several elements that later became common in the Mario series, such as characters Birdo and Shy Guy.

Gameplay
By in large, the gameplay from Doki Doki Panic to Super Mario Bros. 2 remains unchanged. There are only a few differences between the two games as far as gameplay is concerned.
 * Character selection: In Doki Doki Panic, you can still choose from among four characters, but each character's progress through the game is tracked independently. While each character can beat the game, you will not witness the true ending of the game until all four characters have completed the game.  While you can change characters at any point after you die, the next character you choose can only continue from the furthest point in the game that they have completed.
 * Game saving: Because Doki Doki Panic was released on disk format, your progress through the game could be written and saved on the disk. Since you have to play through the game four times, once with every character, in order to see the true ending, saves were a must so that you were not required to play the entire game four times without shutting the machine off.
 * No running: In Doki Doki Panic, is used for nothing more than picking up object or enemies, and throwing them.  Holding down  will not make your character accelerate.  This was only added to Super Mario Bros. 2 because B-button running was such a popular feature of Super Mario Bros.
 * No shrinking: While primarily a cosmetic alteration, the characters of Doki Doki Panic have no "small mode" like the characters in Super Mario Bros. 2 do. Therefore, when you are reduced to one health point, you will not shrink, and when you gain a second health point, you do not grow.
 * A new boss: In Doki Doki Panic, you will face Mouser not twice, but three times in the game. In Super Mario Bros. 2, the third Mouser was replaced by a new boss, Clawgrip, who was designed exclusively for the western release of the game.

Audio and Visual
In constrast to the gameplay, a lot of things about the way that Doki Doki Panic looked and sounded were altered in the transition to Super Mario Bros. 2. The following is a list of features that were changed. Other changes include the following: Sounds were also altered from the original version to the western release.
 * 1-Ups: In Doki Doki Panic, when a player uproots a 1-Up from the ground, they appear as the face of the player in question. In Super Mario Bros. 2, this was changed to a singular 1-Up mushroom that is identical for everyone.
 * Mushroom Blocks: The Mushroom Blocks of Super Mario Bros. 2 did not originally resemble mushrooms at all. Or blocks for that matter.  They were a series of masks that the players would pick up and toss around.
 * Albatoss animation: In Doki Doki Panic, the wing flap of the Albatoss was only animated across two frames. Several in-between frames were added in the western conversion to give Albatoss the far smoother animation that he has today.
 * Ambient animation: In addition to the animation of the grass explained in the table above, several other animated objects from Super Mario Bros. 2 were motionless in Doki Doki Panic. This includes the leaves on the vines, the cherries, POW blocks, bomb fuses, and the surface of water.  On the other hand, many of the waterfalls in the game animated at a much faster rate in Doki Doki Panic, and were slowed down for the western release.
 * Doki Doki Panic had shorter scores for the character select music and the overworld theme. Sub-space and invincibility music was entirely different.
 * 1-Ups originally made the same noise as was made when you completed a level. This was changed to the traditional extra life noise from Super Mario Bros.
 * Several things generate different noises, including enemies when they are picked up and thrown, Birdo, Rockets, POW blocks, collecting cherries, potions/lamps, entering a door, gates opening, getting hit, whale spouts, and StopWatches.