Ben 10: Alien Force

Level Lord cheat:
Go to "Bonus Content" menu, then select the "Enter Code" option, then
enter Gwen, Kevin, Big Chill, Gwen as a code. If the code has been
accepted, go to the "Secrets" menu to activate the newly unlocked cheat.

Infinite Aliens cheat:
Go to "Bonus Content" menu, then select the "Enter Code" option, then
enter Ben, Swampfire, Gwen, Big Chill as a code. If the code has been
accepted, go to the "Secrets" menu to activate the newly unlocked cheat.

Invincibility cheat:
Go to "Bonus Content" menu, then select the "Enter Code" option, then
enter Kevin, Big Chill, Swampfire, Kevin as a code. If the code has been
accepted, go to the "Secrets" menu to activate the newly unlocked cheat.

Unlock all combos:
Go to "Bonus Content" menu, then select the "Enter Code" option, then
enter Swampfire, Gwen, Kevin, Ben as a code. If the code has been
accepted, go to the "Secrets" menu to activate the newly unlocked cheat.

Goop:
Go to "Bonus Content" menu, then select the "Enter Code" option, then
enter Ben, Swampfire, Kevin, Big Chill as a code. If the code has been
accepted, go to the "Secrets" menu to activate the newly unlocked cheat.
OR
Enter Ben, Gwen, Kevin, Big Chill as a code.