Before Pokemon Heart Gold & Soul Silver were released, there were beta pictures from CoroCoro magazine that showed Silver’s, Chikorita’s, Pikachu’s and Pikachu-colored Pichu’s beta sprites. These were changed later on. There is also a beta back sprite of Ethan. His hair is slightly different and there is a symbol on his hat.
Beta screenshots also exist, one of the Slowpoke Well that instead shows a Team Rocket grunt standing where Proton is in the final version, as was the case in the original games, and another of the Mystri Stage in Sinjoh Ruins that shows the three circles being identical instead of three different colors in the final version.
Also, Cyndaquil’s sprite in the intro is different from its front sprite in the main games.
Silver’s beta sprite
Beta back sprite of Ethan
Beta battle screen, showing Ethan and Silver’s aforementioned sprites
Beta Slowpoke Well, minus Proton
Chikorita’s beta sprite (leaf coloring is darker)
Pikachu’s beta sprite
Pikachu-colored Pichu’s beta sprite
Beta version Mystri Stage, a platform in Sinjoh Ruins used for summoning one of the Sinnoh game mascots.
Thanks to Ismaw34 for his contribution!
And other information added in the forums, gabrielwoj found this while editing the rom:
Inside the rom, an folder called “data” have such nice unused things, copied from the older pokemon games:
Underground zones: You know that Pokémon SoulSilver don’t have underground right? At the data folder, files what starts with “ug” (underground) are the sprites from the Underground Cave, like hammer, the maps, the treasures, the traps:
Hammer Animations (click)
Slot Machines: Named as: “slot.narc” The same slot machine from the Platinum version is on the ROM, all in Japanese (even on the Europe/USA rom), included too an Clefairy bonus mode:
Clefairy Bonus Mode (click)
Poketch: Named as “poketch.narc”, there is just, all the poktechs in there, some examples:
Magikarp coin flipper app sprites (click)
^Pokeradar Poketch (remember that doesn’t exist PokéRadar in HeartGold/SoulSilver)
^Dowsing Poketch (Itemfinder)
An additional info found on TheCuttingRoomFloor (Thanks TCRF!), now from below, they were found at The Cutting Room Floor:
Item Bag: The sprites for the D/P male hero’s item pocket selection’s upper screen remain. Missing are the female hero’s purse and Platinum’s white bags.”
Actually, those cited above, have all the sprites from the older pokemons, I think they copied the pokemon platinum and started to edit…
Other 2 items were found at the game, called 0x0070 (Griseous Orb) and 0x0087 (Adamant Orb)
And yet another thing, there is a test object, hidden in somewhere in the rom, but not possible to be opened.