Features

These are some of the new features as of 2.2.0. Some would be spoilers.

We've been greedy in the amount of gameplay elements we've squeezed in there. There's so much included that I even had colleagues saying to me: "Are you sure you should be going this far with a remake?" In that sense, it's not simply a remake—I think it's more than that. For that reason, I would like to see these games enjoyed by as large a number of people as possible.

— Shigeki Morimoto, "Iwata Asks – Pokémon HeartGold Version & SoulSilver Version"

Pokémon

• The New Pokédex order used by the project currently contains 289 entries (see data/pokemon/dex_order_new.asm). Many Johto-appropriate Pokémon (for example, Houndour, Murkrow, and Misdreavus) are available in sensible Johto locations rather than being gated behind Kanto.
• All later-generation Pokémon and forms related to the original Gen 1+2 ones have been added. Examples include Leafeon, Glaceon, Sylveon, Farigifaf, Dudunsparce, Alolan, Galarian, and Hisuian forms, and others (the full list is defined in constants/pokemon_constants.asm and the Pokédex order in data/pokemon/dex_order_new.asm).
• Several Pokémon that were removed in older patches due to engine limitations were later re-included (for example: Spearow, Fearow, Lickitung, Goldeen, Seaking, Hoppip, Skiploom, Jumpluff, Shuckle, Aipom, Stantler, Cleffa, Igglybuff, Smoochum, and Delibird) — see CHANGELOG.md and bsp/save_patches.txt for historical notes and index changes.
• Evolution mechanics are implemented via the project's evolutions table (data/pokemon/evos_attacks.asm). Notable, concrete behaviours include:
  • Eevee family: Leafeon can be obtained either with a Leaf Stone or by leveling in Ilex Forest; Glaceon either with an Ice Stone or by leveling in Ice Path; Sylveon via Shiny Stone (see the evo_data entries in data/pokemon/evos_attacks.asm).
  • Magneton -> Magnezone: Magnezone can be obtained with a Thunder Stone or by leveling in specific locations (MAGNET_TUNNEL or DIM_CAVE) as defined in the evo table.
  • Trade and item-based evolutions: some evolutions use a trade-with-item (EVOLVE_TRADE) rule — e.g., Seadra -> Kingdra via trade while holding a Dragon Scale — while others use holding-item + level (EVOLVE_HOLDING) or item-use rules. The exact method for each species is listed in data/pokemon/evos_attacks.asm.
  • Porygon chain: Porygon -> Porygon2 via UPGRADE; Porygon2 -> Porygon-Z via trade with DUBIOUS_DISC (see evo_data entries).
  • Move- or move-triggered evolutions: several later-gen evolutions are implemented via learning a specific move (for example, Tangrowth, Yanmega, and Mamoswine are implemented via ANCIENTPOWER as an evo trigger in the evo table).
  • Generation II trade evolutions (Machoke, Graveler, Haunter, Kadabra) are implemented as trade evolutions (EVOLVE_TRADE / LINKING_CORD) in the current codebase — they are not implemented as a stat-exp evolution here.

For the authoritative, per-species rules and the complete list of included Pokémon, consult data/pokemon/evos_attacks.asm, constants/pokemon_constants.asm, and data/pokemon/dex_order_new.asm.

Moves

• Added: Acrobatics, Aerial Ace, Air Slash, Aqua Jet, Aqua Tail, Astonish, Aura Sphere, Avalanche, Brave Bird, Bubble Beam, Bug Bite, Bug Buzz, Bulk Up, Bulldoze, Bullet Punch, Calm Mind, Close Combat, Dark Pulse, Dazzlingleam, Disarm Voice, Double Slap, Dragon Claw, Dragon Dance, Dragon Pulse, Draining Kiss, Drain Punch, Earth Power, Energy Ball, Extrasensory, Facade, Feint Attack, Flame Charge, Flare Blitz, Flash Cannon, Focus Blast, Fresh Snack, Fury Strikes, Giga Impact, Gunk Shot, Gyro Ball, Hail, Healinglight, Hex, Hone Claws, Hurricane, Hyper Voice, Ice Shard, Icicle Crash, Icicle Spear, Iron Head, Knock Off, Moonblast, Nasty Plot, Night Slash, Play Rough, Poison Jab, Power Gem, Power Whip, Psystrike, Rock Blast, Roost, Scald, Seed Bomb, Shadow Claw, Shell Smash, Skill Swap, Solar Beam, Sonic Boom, Stone Edge, Sucker Punch, Toxic Spikes, Trick, Trick Room, U Turn, Venoshock, Volt Switch, Water Pulse, Wild Charge, Will O Wisp, X Scissor, Zen Headbutt.
• Removed: Acid Armor, Barrage, Beat Up, Bide, Bind, Bone Club, Bone Rush, Bubble, Bubblebeam, Clamp, Comet Punch, Constrict, Conversion2, Cotton Spore, Detect, Doubleslap, Egg Bomb, Faint Attack, Fissure, Flail, Flame Wheel, Frustration, Fury Attack, Fury Cutter, Fury Swipes, Guillotine, Harden, Horn Drill, Jump Kick, Kinesis, Lock On, Lovely Kiss, Meditate, Mega Kick, Mega Punch, Milk Drink, Mimic, Mind Reader, Mirror Move, Mist, Moonlight, Morning Sun, Nightmare, Poison Gas, Pound, Powder Snow, Present, Psych Up, Psywave, Razor Wind, Rolling Kick, Sand Attack, Selfdestruct, Sharpen, Skull Bash, Sky Attack, Slam, Sludge, Smog, Snore, Softboiled, Solarbeam, Sonicboom, Spider Web, Spike Cannon, Spite, Submission, Sweet Scent, Synthesis, Tail Whip, Triple Kick, Twineedle, Twister, Vicegrip, Vital Throw, Whirlwind, Withdraw.
• Learnsets have been updated close to Gen VI, with missing moves replaced by similar, egg, TM, or event-exclusive moves.

Battle Mechanics

• The Fairy type is implemented. Type-enhancing held items are present: Pink Bow boosts Fairy-type moves (HELD_TYPE_BOOST -> FAIRY), and Silk Scarf boosts Normal-type moves (HELD_TYPE_BOOST -> NORMAL).
• Type chart, base stats, and move attributes all updated to Gen VI.
• Physical/Special/Status split.
• Natures (determined from DVs since personality values don't exist in Gen II) thanks to FredrIQ.
• Gain experience from catching Pokémon.
• Play low-pitched cries when a player or foe Pokémon faints.
• Money loss uses a Gen VI-style formula.
• Shiny Pokémon are determined by the project's shiny flag; the base shiny chance is 1/4096 (SHINY_NUMERATOR = 16). The Shiny Charm and the Masuda method modify this chance in egg/capture logic. The Odd Egg is always shiny.
• Type-enhancing items raise by 20%, not 10%.
• Light Ball doubles Pikachu's Attack as well as Special Attack.
• Critical hits do 150% damage, not 200%, but are more likely.
• Electric-type Pokémon are immune to paralysis, even from Tri Attack.
• Ice-type Pokémon are immune to freezing, even from Tri Attack.
• Fire-type Pokémon are immune to burns, even from Tri Attack.
• Steel-type Pokémon are immune to poisoning.
• Poison-type Pokémon always hit with Toxic.
• Curse is Ghost-type.
• Roar, Whirlwind, and Struggle are unaffected by accuracy or evasion, like Swift.
• Growth raises Attack and Special Attack, by two stages in sunlight.
• Hidden Power is always 70 power.
• Double-Edge and Flare Blitz do 33% recoil damage.
• Twineedle checks for poison after each hit.
• Sandstorm does 1/16 damage per turn.
• Substitute blocks Transform, Swagger, and trapping moves; does not block draining moves; and prevents gaining money from Pay Day.
• Protect works from behind a Substitute.
• Struggle does 25% of max HP recoil damage.
• Sleep lasts 1-3 turns, not 1-7.
• 20% chance to defrost each turn, not 10%.
• Disable lasts for 4 turns.
• Waterfall has a 20% flinch chance.
• X Accuracy boosts accuracy, it does not ignore accuracy checks entirely.
• Leppa Berry (formerly MysteryBerry) restores 10 PP, not 5.
• Sitrus Berry (formerly Gold Berry) restores 25% of max HP, not 30 HP.
• Paralyze and Freeze animations play each turn.
• Rock-type Pokémon get Sp.Def boosted by 50% in a sandstorm.
• Wild Pokémon have more common held items (50% chance for a common one and 5% for a rare one). Giving an Amulet Coin to your lead Pokémon increases this to 60% and 10%.

Overworld Mechanics

• Hold B to use Running Shoes, or turn on the Option to always use them.
• Unlimited-use TMs.
• Continuous Repel system. (You will be prompted when one wears off.)
• Cure poison when it reaches 1 HP outside a battle.
• Eggs hatch at level 1. Abilities or items like Flame Body and the Oval Charm make eggs hatch faster.
• Trees randomly give 1, 2, or 3 Berries.
• Surf at Bicycle/Running Shoes speed.
• Maximum $9,999,999 money and 50,000 coins.
• Bag pocket sizes: Items 75, Medicine 37, Balls 25, Berries 31 (per-pocket capacities; item stacks up to 99).
• Bill will call to warn you when the PC/storage is nearly or completely full. The storage system will automatically place new Pokémon into the next available box if the current box is full, and it reports if the entire PC is full (in which case you'd need to free space).

Maps

• Restored locations from R/B/Y and HG/SS: Viridian Forest, Pewter Museum, Celadon Hotel, Silph Co., Pokémon Mansion, Seafoam Islands, Cerulean Cave, Goldenrod PokéCom Center, and Bellchime Trail, and more!
• New / expanded main overworld locations and features included here (examples):
  • Cinnabar Volcano (multi-floor), Cinnabar Island and related areas
  • A new floor and expanded layout(s) in Rock Tunnel
  • Cherrygrove Bay and expanded Cherrygrove town content
  • Goldenrod Harbor (and Harbour Gate / dual-coast connections)
  • Route 35 coast and several coast/harbour/dual-coast route variants
  • Battle Tower and Battle Factory areas (rematches / postgame facilities)
  • Magnet Tunnel (east/inside/west), Dim Cave (multiple floors), Seafoam Islands, Union Cave expansions, and many additional cave/dungeon floors
  • Multiple islands and special locations: Whirl Island, Valencia Island, Elemental/Faraway/Lucky/Lightning/Ice Islands and associated roofs/inside maps
  • Ruins of Alph (expanded chambers), Sinjoh Ruins, Dragon Shrine / Dragon's Den, Tin Tower expansions, Embedded Tower, and other late-game shrine/tower content
  • Lake of Rage variants (flooded, Magikarp house, hidden power house) and Snowtop Mountain
  • Olivine City additions and route connections (Route 35 coast dual mappings), Blackthorn City and nearby map content
  • Numerous route extensions and gated route variants (many Route NN files for weather/gate/house variants across Johto & Kanto)
• Decorative features added to cities and routes, often from HG/SS.
• HG/SS-style Town Map.

Events

• Team Rocket has another plan to thwart.
• The old Rocket Hideout is repurposed and — by night — is occupied by three leaders (Candela, Spark, and Blanche) who work as teachers by day and are involved in a mysterious project in the hideout.
• Random Wonder Trades in the Goldenrod PokéCom Center, including random held items and original trainers.
• Wonder Trade improvements: post-Elite Four behaviour and bug fixes, Eggs can be Wonder Traded, and a small chance for Wonder Traded Pokémon to have Pokérus.
• Catching all 26 Unown is worthwhile…
• Move Reminder in the same house as the Move Deleter. (Code borrowed from TPP Anniversary Crystal, thanks to its developers graciously making their source code public.)
• Many move tutors throughout Johto and Kanto (about 48 locations).
• Battle Tower and Battle Factory have dedicated events and NPCs (intros, open/closed state, and battle-room trainers such as Anabel, Riley, Buck, Cheryl, Marley, Mira, and others).
• Falkner is in Dark Cave, encouraging you to beat Sprout Tower first.
• Photographing your Pokémon at the Cianwood Photo Studio once a day now makes it happier, like haircuts or massages. (No more GameBoy Printer support.)
• The Mystery Gift girl in Goldenrod Dept. Store gives you a random Berry once a day. (No more Mystery Gift support.)
• The Poké Seer is replaced by the Stats Judge.
• Lt. Surge's electric fences are back.
• Celadon Dept. Store now has a TV Game floor and a Home Decor wing.
• Revised in-game trades.
• Revised Game Corner prizes.
• Revised Buena's Password prizes.
• The Odd Egg is always shiny, with an equal chance to be either gender.
• Three of Prof. Oak's aides give you items as you complete the Pokédex.
• Bill's grandpa gives you one of each evolutionary stone in Goldenrod City. Later they can be bought in Celadon Dept. Store.
• Eusine shows you the legendary beasts in Celadon City in case you haven't found them roaming.
• Respawn any fainted legendaries (except for Celebi) after beating the Elite Four. (Suicune roams instead of appearing in Bell Tower.) (Also respawns Sudowoodo.)

Trainers

• Lyra from HG/SS is your friendly rival. She battles you and gives you some items throughout the game.
• The four Rocket Executives from HG/SS are introduced.
• New trainer classes: Elder, Rich Boy, Schoolgirl, Cowgirl, Battle Girl, Hex Maniac, Guitarist♀, Officer♀, Sr. & Jr., Couple, Breeder, PI, Dragon Tamer, Ace Duo, and Roughneck.
• Battle Lorelei, Agatha, Bill, Valerie, and some other special characters.
• Battle Cal in Viridian City's Trainer House if you're a girl, Kay if you're a boy.
• Rematch the Elite Four at higher levels after earning all 16 badges.
• Rematch Gym Leaders and other special trainers in the Fighting Dojo after earning all 16 badges.
• Battle Tower has new trainers.
• A few NPC trainers have shiny Pokémon.
• Breeders can be rebattled like in B2/W2.

Items

• Revised set of 75 TMs and 6 HMs (see constants/tmhm_constants.asm).
• Four new Poké Balls from Devon Corp.
• Dome Fossil, Helix Fossil, and Old Amber. Revive them in the now-open Pewter Museum of Science.
• All of the decorations for your room are available in different places.
• Earn a Silver Trophy when you beat the Elite 4 and a Gold Trophy when you rematch them at higher levels.
• Other items including Eviolite, Muscle Band, Wise Glasses, Life Orb, Choice Band/Scarf/Specs, Assault Vest, Leftovers, Silk Scarf, and X Spcl. Def.

Bug Fixes

• Dragon Fang boosts Dragon-type moves, not Dragon Scale.
• Burn/Poison/Paralyze improve catch rate.
• Moon Ball catches Moon Stone evolvers.
• Love Ball catches opposite sex.
• Fast Ball catches flee-prone Pokémon.
• Medium-Slow growth rate experience underflow at level 1.
• HP bar lowers at the same speed even for high HP.
• Belly Drum needs to cut HP to raise Attack.
• Lake of Rage Magikarp are larger, not smaller.
• Rocket Executives use Team Rocket battle music, not just Grunts.
• The Ruins of Alph tile with their surrounding maps. (Did this annoy anyone else when making huge maps of Johto?)

Difficulty

• Default Set battle style.
• Enemy AI doesn't fail an extra 25% of the time with sleep or poison-inducing moves, or 40% of the time with stat drops.
• No badge boosts to stats or types.
• Improved some trainers' rosters, movesets, held items, and DVs (particularly Gym Leaders, the Elite Four, and other bosses).
• AI improvements, such as not trying to paralyze Electric types or burn Fire types.
• A smoothly increasing level curve, with the final trainer of the game at level 100.

Changes and Buffs

Pokémon

• Many base stat changes, mostly based on Drayano's Sacred Gold/Storm Silver.
• Blastoise is Water/Steel.
• Butterfree is Bug/Psychic.
• Meowth and Persian are Dark.
• Grimer and Muk are Poison/Dark.
• Farfetch'd is Fighting/Flying.
• Ninetales is Fire/Ghost.
• Golduck is Water/Psychic.
• Meganium is Grass/Fairy.
• Typhlosion is Fire/Ground.
• Feraligatr is Water/Dark.
• Noctowl is Flying/Psychic.
• Ledian is Bug/Fighting.
• Sunflora is Grass/Fire.
• Politoed is Water/Grass.
• Dunsparce is Normal/Ground.
• Electivire is Electric/Fighting.
• Magmortar is Fire/Fighting.
• Rhyperior is Steel/Rock.
• Mismagius is Ghost/Fairy.

Moves

• Attribute differences (per-move):
  • Absorb: pp: 20 -> 25
  • Blizzard: power: 120 -> 110
  • Cut: power: 50 -> 60; type: NORMAL -> STEEL; accuracy: 95 -> 100
  • Dig: power: 60 -> 90
  • Fire Spin: power: 15 -> 40; accuracy: 70 -> 90
  • Flamethrower: power: 95 -> 90
  • Fly: power: 70 -> 90; accuracy: 95 -> 100
  • Glare: accuracy: 75 -> 100
  • Hidden Power: power: 1 -> 70; type: NORMAL -> UNKNOWN_T
  • Leech Life: power: 20 -> 80; pp: 15 -> 10
  • Low Kick: power: 50 -> 1; accuracy: 90 -> 100
  • Minimize: pp: 20 -> 10
  • Rapid Spin: power: 20 -> 50; pp: 40 -> 20
  • Recover: pp: 20 -> 5
  • Rock Smash: power: 20 -> 40
  • Sing: accuracy: 55 -> 75
  • Struggle: type: NORMAL -> UNKNOWN_T
  • Sunny Day: accuracy: 90 -> 100
  • Surf: power: 95 -> 90
  • Swagger: accuracy: 90 -> 85
  • Tackle: power: 35 -> 40; accuracy: 95 -> 100
  • Thrash: power: 90 -> 120; pp: 20 -> 10
  • Thunder: power: 120 -> 110
  • Thunderbolt: power: 95 -> 90
  • Wrap: accuracy: 85 -> 90

I know that not everyone likes this kind of change, so I've provided two ROM patches. The "Faithful" patch keeps the canon Pokémon stats and move attributes.

Graphics and Music

• Restored original Japanese sprites for Beauty, Fisher, Medium, Sage, and Swimmer♀.
• Replaced Twins sprite with a devamped one from B/W.
• New music ported from RBY and devamped from future generations.
• Unique mini sprites for each Pokémon (thanks to this patch).
• Revised some shiny palettes (Dragonite is blue like Dragonair, Nidoqueen is pink like Nidoking, Scizor is silver, Espeon is sky blue, Electabuzz is red, etc).
• Unown isn't the only Pokémon with variant forms…
• Color-coded starter Poké Balls.
• Item balls for TMs are yellow (inspired by Gen VI's yellow).
• Surfing on Pikachu uses the minigame music from Yellow version.

More Tweaks

• Lowercase Pokémon, moves, items, types, names, etc.
• Fast text by default.
• Stereo sound by default.
• Third Trainer Card page for Kanto badges.
• Fourth stats page for capture data formerly told by the Poké Seer.
• Move stats include type, category, power, and accuracy.
• The Mineral Badge, not Storm Badge, makes Pokémon up to L70 obey, like in HG/SS.
• The Zephyr Badge lets you use traded Pokémon up to level 20, like in HG/SS.
• Flash does not require the Zephyr Badge.
• Updated language (Pack → Bag, Enemy → Foe, Cooltrainer → Ace Trainer, Fisher → Fisherman, Elixer → Elixir, Pink Bow → Silk Scarf, new Berry names, etc).
• Brass Tower → Gong Tower (かね kane can mean 金 "metal" or 鉦, a gong-like bell).
• Janine's pink badge is called the Marsh Badge; Sabrina's gold badge is called the Soul Badge. (The Teraleak confirmed this to be a translation error.)
• Fly to the Rock Tunnel/Power Plant Pokémon Center.
• Fishing works 75% of the time, not 50%.
• Nidorina and Nidoqueen can breed, and will produce eggs of either Nidoran gender.
• Always show numbers in Pokédex, even in Johto order.