Pokémon Diamond and Pearl beta

Before their release, went through multiple stages of development, many of which included several things eventually dropped during that period. Some remnants of this data can still be found within the internal data of the games.

Sprites
,, , and all have had prototype sprites from various pre-release pictures and videos, but these sprites have not been found within the data of the final release. Munchlax's sprite seems to be a duplicate from the Munchlax sprite in Pokémon Dash. The Cherrim prototype sprite was shown in an early Japanese commercial. It was surprisingly like the final sprite, only with the left leg up instead. Pokémon.com published prototype sprites during their run up to the release of. Scizor's sprite, as shown on one of the prototype screenshots, depicted the same pose as its final sprite, albeit considerably larger, and using its color palette from the Generation III games rather than the darker palette from the final sprite.

There are also leftover sprites of both the and Team Galactic. Despite the fact that the Ken Sugimori artworks didn't change for the final release, the overworld sprites were different. The rival's sprite featured a slightly different hair style while the Team Galactic Grunts had darker blue hair, somewhat similar in color to Saturn's hair.

Maps
Official pre-release screenshots depicted different designs of certain maps. Two screenshots are of Jubilife City and show the Pokémon Center and the Poké Mart in different spots than the final release. Another screenshot depicted with an unfinished look for water, sand and rocks. The last screenshot depicts, where some early s can be seen.

Camera
Unlike in the final release, which forces a parallel perspective inside most buildings, the three-dimensional perspective view used in the overworld was apparently intended for use in all buildings. Several objects inside of the buildings themselves, through modification of the game's engine camera to force it into its perspective view, have been revealed to actually be fully 3D models, such as tables.

In, buildings that are intended to be viewed in the forced perspective camera lack side walls, only having the back one, while buildings whose interior design is carried over from have side walls fully modeled, such as inside of Pokémon Centers. This modeling of the side walls actually causes a graphical glitch, due to sprites being seen to pass through the walls on their edges, as well as on their shadows.

Pokétch
In multiple pre-release screenshots, an early design for the Pokétch was shown. It had a smaller app changing button and more of the device on-screen. Also, the Digital Clock application was shown without a at the bottom-left corner of the screen.

Font
The font used for the text as seen in the pre-release screenshots of the Japanese versions is very similar to the font used in the Japanese versions of the Generation V games.

Unused Models
In the games, there is also an unused model that is used for shops. It is very similar to the ones placed outside shops in but is independent of the shop model, and they also don't rotate. Through hacking, these models can be loaded to the game and work perfectly fine, except they don't glow, unlike the Pokémon Mart.

Maps
An alternate map for Spear Pillar was discovered. It is similar to the regular Spear Pillar, but the entrance to Mt. Coronet is missing. It is speculated that the Mystery Zone found at the is a possible prototype map.

Mystery Zone with ID  appears to be an unused record mixing room. It plays Pokémon Center (Day) during daytime and Pokémon Center (Night) during nighttime.

Music

 * A remix of Title Screen: Main Theme from can be found in the internal data with a label of  . It can be inferred that it was added during the initial stages of development as either a test track (as per the filename) or as placeholder until Opening Movie was made and added in.
 * An unused remix of Battle! (Gym Leader), that was most likely intended to be used for the  against  can also be found among the internal files under the name.
 * Music played while in the Mystery Zone is a variant of Route 206 (Day). Its filename is an ambiguous, but it has been speculated that it could be an earlier version of the theme.
 * While tweaking and given the undefined is present in an area that the games identify as, a variant of Jubilife City (Day) is played. It is presumed that this theme was an unfinished version of the ordinary theme.

Items

 * S.S. Ticket, the ticket for granting entry on the luxury liner S.S. Anne. It is likely a carryover from.
 * Contest Pass, which would allow entry into . However, allow entry without a pass. Furthermore, the item was only used in, having been unused since.
 * Magma Stone, a mystical item that would have been used at Stark Mountain. Albeit used by NPCs during the undefined's adventure, it is not obtainable by or . It is possible it would have something to do with the  event. This hypothesis would later be confirmed in Pokémon Black 2 and White 2 as  or  obtain the item at, which allows Heatran to be summoned at Reversal Mountain.
 * Red Chain, which is a creation by the lake guardians that would be used to awaken or . Cyrus himself actually uses the item during the plot, and it's possible that the Team Galactic event at the Spear Pillar was initially to be activated by the undefined.
 * , an unusable about using Nintendo Wi-Fi Connection. It's possible that this was removed since these guidelines were included in the instruction book of the games.
 * , an unusable item that holds up to ten Seals, but was replaced with the Seal Case.
 * , a sack for holding treasures from the Underground. It was replaced with a unique menu for the Underground.

Sprites
Back sprites of and, presumably from one of the earliest stages of development, were found. These are possibly leftovers from when Shellos and Gastrodon were planned to be in Generation III. Shellos' sprite is pink, like its, and seems to combine the western variation's head with the 's body, while Gastrodon's sprite is brown and looks like its , but with more rock-like protrusions on its body. Before the release of, this was also considered by some fans to be another "unofficial confirmation" of Pokémon Gold and Silver remakes, since their Pokédex data states that its colors and shapes differ from region to region. However, this proved not to be true due to the similarities to the final forms, and the fact that there are no front sprites for either of the prototype forms. Additionally, there are no known forms of Shellos or Gastrodon that are exclusive to HeartGold and SoulSilver.

The internal data also contains different back sprites for, , , , , , , , , , and – both regular and  forms. Sprites of a  are also available.

Alternate sprites for the, , and Trainer classes, as well as a sprite for the  class, which consists of a male  and a female , were also discovered.

's pose in battle was changed in the European releases as its original posture could have been misunderstood as a Nazi salute. The altered sprite is used in all other Generation IV core series games afterwards.