The following are known Action Replay Codes for Gunstar Super Heroes 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
bd77656e
ff4a7cbe
5bada845
9bf8e41d

Infinite Health
8e4b5d29
799020ea

Super Jump
b7d08ce7
d62335ba
c5c98c68
59ebf4ba