Pokémon HeartGold and Pokémon SoulSilver are Generation IV's remakes of the original Generation II games, Pokémon Gold and Silver. Nintendo released Pokémon HeartGold and Pokémon SoulSilver versions in Japan on September 12, 2009. The games were released in March 14, 2010 for North America and March 26, 2010 in Europe.
- The new female that has replaced Kris is named Lyra, and Gold has been renamed Ethan.
- You receive the Vs. Recorder early in the game by Ethan or Lyra, depending on the gender you chose.
- You have to visit the Sprout Tower and complete the task in it in order to access the Violet City's gym.
- The Global Terminal is found at Goldenrod City.
- All 493 Pokémon can follow you, including the Shiny Pokémon, and you cannot turn off the feature. To do this, you must put the Pokémon at the first in your party (the lead Pokémon), then it will appear behind you. You may also interact with it to show how it feels right now.
- All the gyms are harder.
- The tiles of the puzzle in Ruins of Alph can be rotated to solve the puzzle. Players who succeeded solving the Kabuto puzzle will receive an Unown Dex from a man in the ruins.
- Team Rocket now have four executives - Proton, Petrel, Ariana, and Archer. Their appearances can be found in the intro video.
- Eusine (from Pokémon Crystal) makes a debut, he is a character who is interested in Suicune. The player will meet him when the player found Suicune. His appearance also can be found at the intro video, which is a man wearing purple clothes. He will be seen whenever the character will encounter Suicine.
- Additional routes, Route 47 and Route 48 is placed next to Cianwood City. A Safari Zone can be found at Route 48, owned by Baoba.
- The areas in the Safari Zone can be altered after you receive the second challenge Baoba gives you.
- Just like in the original Gold, Silver, and Crystal, there are many day based activities like the Bug Catching Contest, Goldenrod to Saffron City train, Olivine to Vermilion City ship, etc. These are also on the days they were in the originals too.
- Next to the National Park there is the Pokéathlon Dome in which you can compete in minigames to win medals, which is open after you receive the Plain Badge.
- The move Flash is now a TM move.
- Hills that required HM08 Rock Climb can now be found.
- Some trainers in Kanto region have Generation III and IV Pokémon .
- The Battle Frontier at Route 40 replaces the Battle Tower.
- The Pal Park replaces the Kanto Safari Zone in Fuchsia City.
- There is Viridian Forest in Pokémon HeartGold and SoulSilver, which the earlier versions do not have (Pokémon Gold, Silver, Crystal), though the earlier games had a forest but with no Pokémon in it.
- The radio functions in the PokéGear have been altered, which the player can manually tune the channel to listen, or pressing one of the four buttons to gain immediate access to the channels available.
- Some channels have to be manually tuned, and must be standing in a specific location.
- Poké Flute - Must be in the Kanto region, tune manually to the upper middle section. This radio channel helps to wake up the Snorlax in Route 11.
- Mysterious Transmission - Inside the chamber of Ruins of Alph, manually tune the music to the center. It produces a strange sound, which is produced by Unown. It helps to increase the chance of meeting a rare-shaped Unown.
Elite Four and Champion
- The Poké Walker is a handheld pedometer that resembles a Poké Ball. It was sold with the HeartGold and SoulSilver Pokémon games.
- The Poké Walker can connect to HeartGold and SoulSilver cartridges via infared signals and can "hold" one Pokémon that you then carry around with you.
- A Pokémon being carried around in this manner will recieve experience points and closeness, as well as the player gaining "watts", an in-game currency that can be used to find and catch wild Pokémon, search for items, and unlock new locations within the Poké Walker.
- Up to three Pokémon can be captured and stored on the Pokewalker, but only one will appear on the inventory screen.
- You will also be able to receive items through other Poké Walker devices using infared.
- The Poké Walker is similiar to the Pokémon Pikachu 2 pedometer/virtual pet in its use of Watts as currency to trade for items.
- You can get one of the Johto Starters from Professor Elm at the beginning of the game.
- You can get one of the Kanto Starters from Professor Oak after beating Red.
- You can get one of the the Hoenn Starters from Steven after beating Red.
- No Sinnoh Starters without trading.
- The player can get both Ho-oh and Lugia on both games. The version mascot will be level 45, while the other will be level 70. To get them, however, the player must have all eight Johto gym Badges and defeat the Kimono Girls in Ecruteak City first for the version mascot and get the Clear Bell in HeartGold or the Tidal Bell in SoulSilver.
- The Legendary Dogs (Entei, Raikou and Suicune) are all level 40, but Suicune, despite its speed in the game and the anime, is not a roamer unlike the other two and gets caught by the player at a predetermined point in the game.
- Unlike the original games you can get the three Legendary Birds (Articuno, Zapdos and Moltres).
- Groudon can be obtained in SoulSilver, whereas Kyogre in HeartGold. Both required a certain orb in order for them to be available for capture. The orbs can be obtained by Mr. Pokémon when you obtain the National Pokédex and a starter Pokémon in Kanto. (Red Orb for Groudon, Blue Orb for Kyogre) They can be captured in Embedded Tower, located in Route 47.
- Rayquaza can be obtained if you have both Groudon and Kyogre. The Groudon and Kyogre must be traded from either HeartGold or SoulSilver, not from the older versions (Ruby, Sapphire or Emerald). Receive the Jade Orb from Professor Oak after capturing the two Pokémon. It can be captured in the Embedded Tower.
- You get one of the Sinnoh legendary dragons (Dialga, Palkia or Giratina) at level 1 from the Arceus Event in the Sinjoh Ruins.
- You can get the Eon Pokémon (Latias and Latios) in the Kanto region.
- Celebi is also an attainable Pokémon from an event.
- You can find Mewtwo deep in Cerulean Cave once you have all the Kanto badges.
- Like in the originals, you can obtain Sudowoodo at Level 20.
- You can also get Lapras in Union Cave at level 20 each Friday.
- The infamous Red Gyarados is at level 30. (It is a water-flying type, so be careful with the electric attacks!)
- You can catch a Snorlax at Route 11 at Level 50, which is blocking the Diglett Cave, and you have to wake it up to capture by playing the Poké Flute in the PokéGear.
- When you have the event Pikachu Coloured Pichu , go to the Shrine in Ilex Forest and then you will have chance to get the Notched Eared Pichu (or for the US and Europe Spiky Eared Pichu). The Pichu is given to you, so you don't have to waste Poké Balls.
- Fish or sea Pokémon can follow the player on land, although they have to live in water.
- Legendary or large Pokémon cannot follow the player when the player enters a building.
- Lyra appeared in the anime in a 5-episode arc to promote HGSS.
- In both versions you get to fight both Red and Blue (from FireRed and LeafGreen versions).