How do you unlock ALL Lego Batman characters?

Well, look for all the stations you can already activate, for every station you activate, you get more characters. THOSE characters can activate MORE stations, etc etc... look for hovering characters like R2-D2, Jango Fett, and Boba fett, they help because they fly instead of jump, the can save you jumping time, Jar Jar for example is much easier to find if you have a hovering character. you can learn how to get Boba in the second paragraph. My advice for scouting for stations? NEVER use a battle droid! they suck at jumping, and they only activate one station in the whole game, Obi Wan's.

BUT there ARE 10 other characters that are covered by ?s. Search (on this same website) the question, "What are all the codes for LEGO Star Wars: III beta?" it should show codes for Darth sidious, Vader, Savage Oppress, Han solo, chewbacca, Luke skywalker, Leia,Boba fett, Lando calrissian, and even Ben Kenobi!

Finally, after that there should be one more spot covered by a padlock, all you have to do to uncover that is share five videos (trailers for the game, gameplay vids, etc) on facebook. That character is Darth Maul, who only appeared in Star Wars: Episode I: The Phantom Menace!