The following are known Action Replay Codes for Dark Arena on Nintendo Game Boy Advance (GBA).
These codes were also known as GameShark Codes and in most cases will work on both devices.

These codes are for the U.S. version of the game.

Master Code – Must Be On
de7ace69
c5c4e1a7
7d047b9e
19bbf58e

Infinite Health
2a2be1d4
c11c9c5c

Infinite C. Rifle Ammo
7701bcd4
420288dd

Infinite Bolt Gun Ammo
ff01774c
ce538888