Unlock the following cheats by winning platinum medals in Challenge mode.
To win a platinum medal you must complete all three primary objectives in any one Challenge mode match. This will then allow you to play that same match again with the chance to win a platinum medal by completing the platinum objective. The platinum objective will be listed under the primary objectives.
Note: You must complete all the primary objectives before the end of the match to get the chance to play the platinum objective.
Also, these unlockables will only be playable in Play Now mode.
You can quit the game once you have achieved the platinum objective; you do not have to play out the entire match.