Bug Blox

Bug Blox (バグブロックス) are computer bugs in the shape of a cube that appear as a critical part of the gameplay in Kingdom Hearts coded and Kingdom Hearts Re:coded.

Kingdom Hearts coded
Bug Blox 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 Blox 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 Blox. 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, including a new enemy type.