Gameplay
The new Unova Link is introduced, which makes way for new features.
Challenge Mode and Easy Mode are introduced, which raise and lower the strength of opposing Trainers respectively.
A new feature called the Memory Link is introduced, which reveals flashbacks from the NPCs that shed light on events that happened between Black and White and Black 2 and White 2.
Many TMs and all but one HM are received in different locations.
The Xtransceiver adds two new mini-games called Balloon Catch, where the player needs to catch balloons of their face or an NPC's, and Balloon Smash, where the player needs to inflate the balloons as large as possible without bursting them.
The Move Tutors are back, and as with Pokémon Platinum, they teach most of the moves that were in that game for Shards, but here they all ask for shards of a specific color. They also teach many moves that lost their TM status, such as Dark Pulse, Roost and Stealth Rock.
If the player has used a Repel, after its effect wears off, and if the player has more Repels in their Bag, they will be asked if they would like to use another immediately without having to go into the menu.
A number of legendaries from Hoenn and Sinnoh (excluding the Weather trio and Creation trio) can be found in the post-game.
Zorua, Zoroark and TM95 (Snarl), which were previously accessible through Nintendo events only, can now be found within the game without any special requirements.
The Forces of Nature are notably the only Unova regional Pokémon absent from either game and must be obtained through the Pokémon Dream Radar and then transferred or alternatively they can be traded from Black and White. The Dream Radar is also necessary to obtain their new forms.
Breeding was changed—the Everstone now always passes down Nature (if both parents hold Everstone, one parent's Nature is randomly picked).
All Pokémon Breeders will now challenge the player again every time the player crosses their line of sight after exiting and re-entering the areas in which they are found.
Hidden Grottoes are introduced and scattered all over Unova, giving access to many items and Pokémon with their Hidden Abilities, many of which were previously unobtainable.
Watchog's EV yield is changed from 1 Attack to 2 Attack.
Players can now move held items between Pokémon in their party.
Storyline
The player no longer starts in Nuvema Town, instead starting in Aspertia City.
Instead of the usual 5 Poké Balls, the player is given 10 at the start of his or her journey.
Chili, Cress, Cilan; Lenora and Brycen are replaced by Cheren, Roxie and Marlon as Gym Leaders, respectively.
Bianca gives the player a starter Pokémon in Aspertia City.
A new Team Plasma has formed, and is run by Colress, who battles the player frequently throughout the story. Ghetsis is once again the secret mastermind behind the Team, now planning to freeze Unova with Kyurem.
Rood, Zinzolin and the Shadow Triad are battled as part of the story.
The Gym Leader order has changed to Cheren, Roxie, Burgh, Elesa, Clay, Skyla, Drayden, Marlon.
Alder is replaced by Iris as the Champion of Unova.
N returns to Unova with either ZekromB2 or ReshiramW2, who is then fused with Kyurem to form either Black KyuremB2 or White KyuremW2.
Unlike Pokémon Black and White, neither the game mascots Black KyuremB2 or White KyuremW2 can be caught within the story, but can be obtained post-game by following certain requirements.
Cobalion and Virizion interact with the player, making it possible to catch them during the storyline, although it is possible to catch all three Pokémon including Terrakion.
Several tag battles take place throughout the game: one with the other player character, two with Cheren, four with Hugh, one with Bianca, and a daily tag battle with one of either Chili, Cress, or Cilan against the other two brothers.
A new attraction known as the Pokémon World Tournament opens up in Driftveil City, where the player battles Gym Leaders and Champions from all five regions, among others.
Another new attraction introduced is the Pokéstar Studios, located in Virbank City, where the player takes part in many different movies. Brycen and Sabrina appear here.
Lenora revives the player's Fossils.
Several new Key Items exclusive to Black and White 2 are introduced.
During the post-game, the player may find N at his castle and on the first visit, battles his ZekromB2 or ReshiramW2, who is free for capture after defeating N. Subsequent battles can be done once a season and feature N using a team of Pokémon centered around that season.
Several areas that were previously limited to the post-game of Black and White are now part of the main story. In contrast, some of the areas that were formerly part of the main story are now limited to the post-game.
Graphics
The opening is drastically different from the one in Black and White, now featuring the new game characters, the Tao trio and the Swords of Justice. Also, the title screen shows either Black Kyurem or White Kyurem, depending on the version.
The bar that shows a Pokémon's level, experience points, and HP has been redesigned. It is black in Black 2 and white in White 2.
The area change indicator has also been redesigned and shows the location in the top left of the screen and season in the bottom right. It is black in Black 2 and white in White 2.
New locations such as Aspertia City, Virbank City, Floccesy Town, Lentimas Town and Humilau City have been added to the game.
New characters are introduced, such as Hugh, Colress, Roxie, Marlon and Benga.
Cheren, Bianca, Elesa, Ghetsis and Iris all receive redesigns.
All Unova Gyms receive redesigns, including newly remixed music in all but the Aspertia Gym.
Most of the Black and White music has been slightly remixed, in addition to the Gym Leader and Champion music from Kanto, Johto, Hoenn and Sinnoh.
There have been several changes made to existing locations, such as Driftveil City and Nimbasa City.
Every Trainer has their own fully animated sprite. They have more frames, allowing for smoother animations.
Several attacks have received new battle animations.
The battle menu has been redesigned.
The C-Gear has been redesigned.
The Unova Pokédex has been expanded tremendously to accommodate older Pokémon.
It also receives a slight aesthetic change, now having a red background instead of green.
The Pokédex also receives an upgrade in the form of the Habitat List. It consists of a list of all visited places, with the Pokémon found there listed (if they have been seen). The player will sometimes receive prizes from certain NPCs when a certain area is filled.
All returning Gym Leaders and Champions receive new sprites. This also applies for the overworld sprites.
Route 4 has changed drastically and also differs between Black 2 and White 2.
Victory Road changed drastically from Black and White to Black 2 and White 2 as well and differs in appearance between Black 2 and White 2. It has also changed location.
Challenger's Cave's entrance collapsed, while Route 10 was blocked off due to a landslide on Victory Road, making both areas inaccessible.
In place of Cold Storage, there is now the Pokémon World Tournament.
Places marked on the map with green dots in Black and White are now marked with green squares. Also, now when they are tapped they become red (though they still cannot be flown to). This was only true of Liberty Garden in Black and White.
During battles in tall grass, there are now visible tufts of grass around the platform, with varying colors depending on the season.
Following the battle at Opelucid Gym, Team Plasma will freeze Opelucid City (along with a portion of the neighboring routes, Route 9 and Route 11), which will last until after the player has entered the Hall of Fame.
The weather icons have been redesigned and are smaller.
Features
Pokémon World Tournament
Main article: Pokémon World Tournament
A new facility featured in Black 2 and White 2 is the Pokémon World Tournament, where the player is able to battle every Gym Leader and Champion (except Koga and Iris) from the core series games in various types of battles.
Pokéstar Studios
Main article: Pokéstar Studios
Pokéstar Studios is a new feature in the games that allows the player to take part in making films involving Pokémon. The player chooses from various scenarios and acts them out.
Medals
Main article: Medal
Medals is a new type of achievement system. They are obtained from Mr. Medal at any Pokémon Center and are stored in the Medal Box.
Seasons
Main article: Seasons
Seasons once again return to the games. In addition to covering the entire screen upon starting the games, a text box appears at the bottom of the screen presenting the current season every time a new area is entered.
Word filter
The filter that censors certain words in name inputs remains. The restriction on using four numerical digits is removed but only for Box names in the Pokémon Storage System.
Sprite animations
Just like in Pokémon Black and White, the Pokémon sprites are fully animated and move throughout battles. However, unlike Black and White, every Trainer in the game has battle animations, as well as more frames which allow for smoother animations.
The game also introduces new entry sprite animations for Pokémon, much as if it were a Shiny Pokémon.
N's Pokémon, which are obtainable through Memory Link, (with the exception of N's Zorua, who is obtainable during the main plot) have a green/yellow diamond shine, along with their own sound.
Also, in the Pokéstar Studios, when a player successfully completes a movie with their Pokémon in an unusual matter by deviating from the script, their Pokémon will become a star and during battles, when the Pokémon is summoned, a star will bounce upwards and then back downwards. This is the only entry animation that can be added manually by the player.
Gyms
Within the two years separating Black 2 and White 2 from their predecessors, some of the past Gym Leaders have passed on their positions to others or retired from the Unova League. The eight Gym Leaders of Unova are now: Cheren (Normal), Roxie (Poison), Burgh (Bug), Elesa (Electric), Clay (Ground), Skyla (Flying), Drayden (Dragon) and Marlon (Water).
Each Gym has different music from the others. Aspertia Gym uses the normal Gym theme (probably due to the fact that it is a Normal-type Gym), while other Gyms use remixed versions, which are influenced by the type used and the Gym Leader's secondary occupation.
Elite Four and Champion
Like Black and White, the Elite Four can be battled in any order; after battling all four, a path to the Champion is unlocked. The Elite Four members are Shauntal (Ghost), Grimsley (Dark), Caitlin (Psychic), and Marshal (Fighting). The new Champion is Iris.
