The following are known Action Replay Codes for Arcade Classic No. 2: Centipede / Millipede on Nintendo Game Boy / Color (GB / GBC). These codes were also known as GameShark Codes and in most cases will work on both devices.

Device Compatibility: Action Replay & GameShark

Infinite Lives Centipede
0103a0c6

Infinite Lives Millipede
010329d6