Pokemon HeartGold Version Cheats on DS

National Dex

Beat the Elite Four once and go to the S.S Aqua ship in Olivine City to get the National Dex.

Trainer Card colors

Complete the indicated task to unlock the corresponding color. You can earn stars by completing the following tasks: defeating the Elite Four, finding all Shining Leaves, and capturing all 493 Pokemon (not including event-only Pokemon).

Unlockable	How to unlock
Black Card	Earn five stars.
Blue Card	Earn one star.
Bronze Card	Earn two stars.
Gold Card	Earn four stars.
Silver Card	Earn three stars.

Restart the Game

Simultaneously press L + R + START + SELECT to reset the game.

Pokewalker maps

Complete the indicated task to unlock the corresponding map.

Beautiful Beach: Get 200 Watts.
Beyond the Sea: Get a foreign Pokemon by using the GTS.
Big Forest: Get 40,000 Watts and own the National Dex.
Blue Lake: Get 2,000 Watts.
Dim Cave: Get 1,000 Watts.
Hoenn Field: Get 5,000 Watts and own the National Dex.
Icy Mountain Rd.: Get 30,000 Watts and own the National Dex.
Night Sky's Edge: Trade a fateful-encounter Jirachi onto Pokemon HeartGold or SoulSilver.
Noisy Forest: Available by default.
Quiet Cave: Get 100,000 Watts and own the National Dex.
Rally: Participated in the Wi-Fi Event during January 29th through February 28th, 2010 in Japan.
Refreshing Field: Available by default.
Resort: Get 80,000 Watts and own the National Dex.
Rugged Road: Get 50 Watts.
Scary Cave: Get 20,000 Watts and own the National Dex.
Sightseeing: Participated in the Wi-Fi Event during November 14th, 2009 through to January 11th, 2010 in Japan' and from April 17th to May 31st, 2010 in Korea.
Sinnoh Field: Get 25,000 Watts and own the National Dex.
Stormy Beach: Get 65,000 Watts and own the National Dex.
Suburban Area: Get 500 Watts.
Town Outskirts: Get 3,000 Watts.
Tree House: Get 15,000 Watts and own the National Dex.
Volcano Path: Get 10,000 Watts and own the National Dex.
Warm Beach: Get 7,500 Watts and own the National Dex.
White Lake: Get 50,000 Watts and own the National Dex.
Winner's Path: Participated in the Wi-Fi Event from May 6th to June 25th, 2010.
Yellow Forest: Participlated in the Wi-Fi Event from April 1st to May 5th, 2010.

Secret box wallpapers and Pokemon eggs

Go to the Violet City Pokemon Center. Notice the man next to the PC. Tell him certain words when he asks you for your opinion. Use this site to generate these words. This will unlock special box wallpapers and Pokemon eggs in your game.

Ruins of Alph: Hidden items

In the same rooms where you have to complete a picture puzzle of Omanyte, Kabuto, Aerodactyl, or Ho-Oh, there is a plaque that has a word that is spelled using Unowns. Do the following steps.

Room with the Kabuto Puzzle: The word is "Escape". You must use an Escape Rope facing the plaque. You can easily get an Escape Rope at the Violet City Pokemart. The four items obtained are Energy Powder, Heal Powder, Oran Berry, and Pecha Berry.
Room with the Aerodactyl Puzzle (accessible by Surfing): The word is

! and ? Unown

After you have collected all other twenty six Unown (A through Z), the ! and ? Unown will appear in the Hall Entrance.

Dragon Ball Z reference

In Ecruteak City at the Dance studio, a Team Rocket grunt is hassling a kimono girl. Talk to the person on the right side of the stage. He tells you he would have put a stop the grunt's behavior if it was not for the incredible pain of his stomachache. This is a tactic commonly used by Hercule Satan in Dragon Ball Z to get out of fighting.

Game Boy reference

At Celadon City, enter the Celadon Condominiums next to the Pokemon Center. Use the elevator to reach the third floor. When you exit, your friend will tell you about the GB Sounds. Talk to the man next to the globe after collecting all of the Kanto badges to get the GB Sounds Device.

Split and fused poles

When you go to the back of the Safari Zone where the poles are, they will split in two or fuse together depending on where you are standing.