Gladius

Camera Control
Pause the game during combat, then press: Up, Left, Down, Right, Left, Left, Left, Left, Up, Up, Up, Up.
(Thanks to stewartadicom@msn.com)

Decrease Enemy Difficulty
Pause the game in a league office, then press: Right, Right, Right, Up, Up, Left, Left, Left, Left, Right, Down, Down, Down, Down, Up .
This code can be repeated.
(Thanks to stewartadicom@msn.com)

Earn Extras
There is a lot of extra equipment and money to be earned by mastering the competition, which is done by winning all challenges under a league tier. In some instances, you will even win powerful new allies to assist you, such as Yeti and Skeleton Summoner.
(Thanks to stewartadicom@msn.com)

Easy Gold
Hire a new gladiator, remove his armor and helmet, then expel them. You can usually sell their armor for anywhere from 9000 to 19000 making a lot of gold when you repeat the process.
(Thanks to stewartadicom@msn.com)

Increase Enemy Difficulty
Pause the game in a league office, then press: Right, Right, Right, Up, Up, Left, Left, Left, Left, Up, Up, Up, Up, Down.
(Thanks to stewartadicom@msn.com)

Unlimited Equipment
Pause the game at the school menu, then press: Right, Down, Left, Up, Left, Left, Left, Left, Y, Y, Y.
(Thanks to stewartadicom@msn.com)