Bug Block

Bug Blocks (バグブロック, Bagu Burokku) are computer bugs in the shape of a cube that appear as a critical part of the gameplay in Kingdom Hearts coded.

Kingdom Hearts coded
Bug Blocks appear in all of the Data Worlds from Jiminy's Journal; they are a product of the data "bugs" from digitizing the journal. The Data Sora must destroy Bug Blocks in order to progress through worlds and the storyline, as well as fix the Data Worlds.

In Episode 8, it was revealed that Naminé's manipulation of Sora's memories in Kingdom Hearts: Chain of Memories was the primary cause of the appearance of the Bug Blocks. The Data Naminé confirmed this to King Mickey and the Data Sora, along with informing them of the suffering of some connected to Sora's heart, namely Terra, Aqua, Ventus, Roxas, the real Naminé, Axel, and Xion.

Varieties
There are different types of blocks with different designs and effects. Kingdom Hearts Re:coded added additional blocks and color coding. They include:
 * Normal Blocks (ノーマルブロック): Breakable blocks. They are colored red and marked with a design resembling organic circuit lines with circular patterns.
 * Metal Blocks (メタルブロック): Unbreakable blocks. They are colored metallic silver with the same markings as Normal Blocks.
 * Damage Blocks (ダメージブロック): Blocks that inflict damage on contact. They are marked with a jagged thorny pattern, and are colored red in Kingdom Hearts coded and yellow in Kingdom Hearts Re:coded.
 * Bound Blocks (バウンドブロック): Blocks that bounce you back on contact. They can be used to reach high locations. They are colored blue with a circular pattern that resembles an amoeba. They appear only in Kingdom Hearts Re:coded.
 * Ghost Blocks (ゴーストブロック): Blocks that have faces that appear and disappear. They are colored green with the same markings as Normal Blocks, as well as a static effect. When the faces disappear, the glowing green border is left behind. They appear only in Kingdom Hearts Re:coded.
 * Prize Blocks (プライズブロック): Breakable blocks that contain prizes or item boxes. They have a pink and blue checkered pattern with a star on each face and a gold border.
 * Rare Prize Blocks (レアプライズブロック): Breakable blocks that contain rare item boxes. They have a shiny gold appearance with a silver star on each face and a silver border. They appear only in Kingdom Hearts Re:coded.
 * Pair Blocks (ペアブロック): Blocks that appear in pairs. When struck together, they fuse into a new block that gives Prizes when destroyed. Their design resembles that of Prize Blocks and Rare Prize Blocks, with a dark blue coloration on one of the pair, and a dull yellow coloration on the other.