The following are known Action Replay Codes for TimeSplitters: Future Perfect on Nintendo GameCube (GCN).

Master Code – Must Be On
4JD4-773G-E1P3W
PQWW-Y0YF-7V959

Infinite Health
9UYZ-AW4U-83125
KV8H-TFF0-HVPW2
K8E7-JHBE-X13R1
QG0D-5PQ2-WQ35W

Infinite Ammo
9VKE-9U6W-QF4D6
94R6-UDFK-A17H3
MZVW-R44F-W9QD9

Some Timers Frozen
7KFT-UXBV-5J9KF
RE6W-N5M3-Y5M0E

Game 100% Complete
FJMH-PXN2-RWWYK
CY71-7NP8-BR8Y9
4WXD-0C19-KFUYX
N7Y7-638N-3N5WB
MU39-0RJB-BG18C
B2Z7-43A9-7NKA0