Entering Codes
Go to the Batcave if you are in a level by pressing "Start" to pause the game, then selecting "The Batcave" and press the "A" button. Go to the computer console on the upper level of the Batcave and stand directly in front of it. Select "Enter Code" and press the "A" button. Use the up and down buttons on the D-pad to select the letters and numbers for the codes.
The Joker
Enter the code "CCB199" into the computer and press the "A" button to unlock Tropical Joker. You can confirm that this process worked by noting the message flashing at the bottom of the screen that says "The Joker (Tropical)." You will now be able to select the Tropical version of the Joker in "Free Play" mode. Entering the code "JUK657" into the computer will unlock the Joker's van.
Other McDonald's Toy Codes
Other McDonald's toy unlockable codes: "XWP645" -- Expanded Batarang Targets, "DDP967" -- Commissioner Gordon, "BDJ327" -- Bruce Wayne, "NJL412" -- Yeti, "MAC788" -- Police Van, "MAC788" -- Penguin Minion, "MVY759" -- Nightwing. All of these can be unlocked from Batman's computer in the same manner as the Tropical Joker.
Cheat Codes
In addition to all of the other unlockables, there are a number of cheat codes that can enhance your "Lego Batman" gameplay. The cheat codes are as follows: "ML3KHP" -- extra hearts; "18HW07" -- 10-times score multiplier; "WYD5CP" -- invincibility; "N8JZEK" -- armor plating for the detonator suit; "GHJ2DY" -- fast Lego block building; "MMN786" -- power brick detector; "WCCDB9" - 8-times score multiplier; and "LK2DY4" -- attracts Lego studs to your character.