Tetris Battle Gaiden (テトリス バトル外伝 武闘外伝, Tetorisu Batoru Gaiden Butō Gaiden) is a competitive puzzle-battle game, similar to games such as Puzzle Fighter or Puyo Puyo. One can play against a friend or the Computer in a story mode. There is also an included Rensa mode, which ensures a more hyperactive game due to increased gravity. The player can choose from a list of characters in the story mode, including a Dragon or a pumpkin named Halloween.
Tetries Battle Gaiden differs from classic Tetris in its puzzle-fighter style game play. A player will draw from the same 3 piece preview as his opponent. The goal is to fill the opponents screen with blocks. The easiest way to do this is through the use of power ups. These power ups are obtained through the collection of orbs. These orbs are gained when they are dropped in the normal Tetris blocks. When the orbs are cleared, a power up is obtained. Power ups are unique to each character, and can include an earthquake, orbital laser, mirror shield, or the ability to knock away an opponents piece.
The game has three separate modes to select from in the Settings options. They are Battlis, Tetris, and Rensa.
Battlis is the standard game mode.
In Rensa mode, all the magic stays suspended where they originally land in the pattern and will not drop, but all other pieces are effected by gravity and will drop to the bottom if nothing is underneath. Rensa (連鎖, rensa) is the Japanese word that means "chain" or "connection".
There are 8 playable characters in Battle Gaiden, all with 4 attacks each. The game's two bosses, Dragon and Queen, are also playable characters by entering the following code on the copyright screen: B, B, X, X, A, Y, A, Y, Up, Left. The copyright text will turn blue. At the character select screen, hold L+A when picking a character to play as Dragon, R+A to play as Queen.
Halloween (The Pumpkin Head)
- Fry (フライ, Furai): Makes the bottom 4 lines complete. These will be removed upon placing the next piece.
- Dark (ダーク, Dāku): Makes the opponent's screen dark for 3 pieces.
- Vampire (バンパイア, Banpaia): Steals the opponent's crystals in their queue and places it in their own.
- Bomb (ボム, Bomu): Bombs the opponent's side, leaving them with scattered gaps in their entire well.
Mirurun (Pink Bunny)
- Mirurun (ミルルン, Mirurun): Smashes down the bottom 4 lines.
- Reversal (ハンテン, Hanten): Turns the opponent's controls upside down. Hanten is the Japanese word for "reversal" or "inversion".
- Pentarisu (ペンタリス, Pentarisu): Pushes the opponent's side up.
- Suritote (スリトテ, Suritote): Inverts the blocks and gaps of the opponent's side up the the highest level.
Shaman (The Tiki Man)
- Moses (モーゼ, Mōze): Pushes the center to the sides and drops to fill holes, except crystal pieces.
- Rotation (カイテン, Kaiten): Opponent's down button is rotation. In Japanese, kaiten means "rotation".
- Curse (ノロイ, Noroi): Stone blocks comes up on opponent's side as they play pieces; more if lines are sent. In Japanese, noroi means "curse" or "spell".
- Prayer (イノリ, Inori): Random level 4 of other characters. However, you may Medusa yourself. In Japanese, inori means "prayer".
- Seesaw (シーソー, Shīsō): Pushes the bottom two lines over to opponent.
- Shield (シールド, Shīrudo): Protects you from lines being sent to you.
- Fax (ファックス, Fakkusu): Faxes an image of your current layout to opponent, giving them the same one as you.
- Remote Control (リモコン, Remokon): Control two pieces of your opponent.
- Shave (ソル, Soru): Zaps away a column spanning 3 squares. Player chooses what section to laser. In Japanese, soru means "to shave".
- Mirror (ミラー, Mirā): Reflects opponent's crystal attack.
- Paralysis (マヒ, Mahi): Causes opponent to not have rotation for three pieces. In Japanees, mahi means "paralysis" or "numbness".
- Copy (コピー, Copī): Copies the opponent's layout.
Bit (The Peoples)
- Stardust (スターダスト, Sutādasuto): A shower of stars scatter over the board. These stars delete all the excess pieces on the horizontal row that they land on.
- Fever (フィーバー, Fībā): Repeats the current piece for both players, and this includes the magic if it's in that piece.
- Gang (ギャング, Gyangu): Steals the opponent's crystals from their area and puts them into the player's queue to then use.
- Mambo (マンボ, Manbo): Shakes up opponent's block arrangement, and the dimensions of the gaps persists.
- Gather (ヨセ, Yose): Pushes everything to one side. In Japanese, yose means "gathering" or "coming together".
- Deception (マヤカシ, Mayakashi): Causes the opponent to get random pieces that are not what the preview field shows. In Japanese, mayakashi means "deception" or "forgery".
- Mess (ダイナシ, Dainashi): Puts a web up on opponent's side which prevents completed pieces from falling. In Japanese, dainashi means to "mess" or "spoil" something.
- Medusa (メデューサ, Medūsa): Turns the other side into stone. A single line must be done twice to disappear.
Wolfman (The Samurai)
- Cut (カット, Katto): Cuts away the top four lines.
- Nu (ヌー, Nū): Opponent cannot use down button to quickly drop pieces.
- Buddies (ナカヨシ, Nakayoshi): As the opponent sends you lines, your side goes down instead of up. In Japanese, nakayoshi means "close friend" or "buddy".
- Earth Release (ドトン, Doton): When one line gets completed, it causes all pieces to fall, except where the crystals are. In Japanese, Doton (土遁) translates as "earth release", but can also be read as "earth style".
There are two boss characters that aren't shown in the main character select screen and have unique Lvl. 1-4 powers.
- Press (プレス, Puresu): A recovery technique that is a combination of Ninja's "Gather" and Mirurun's "Mirurun" techniques.
- Select (セレクト, Surekuto): Allows the change of the block using the L and R keys.
- Roulette (ルーレット, Rūretto): Mixes up the button layout of the opponents controller randomly.
- Change (チェンジ, Chenji): Copies and switches the boards of the two players.
- Hyper Fry (ハイパーフライ, Haipā Furai): A stronger version of Halloween's Fry.
- Reverse (リバース, Ribāsu): Reverses right and left of the other player's controller.
- Doubles (ダブルス, Daburusu): Doubles the feed of blocks to the opponent.
- Clear (クリアー, Kuriā): Removes all the blocks on the the player's own field.