Alternate costumes
The following characters can be unlocked by spending the indicated amount of Justice League of America shields that can be collected during game play.

Code – Effect

Batman (Batman Beyond infiltration suit) – 74 shields
Batman (classic blue) – 59 shields
Flash (Jay Garrick) – 21 shields
Flash (Walter West) – 48 shields
Green Lantern (bold) – 30 shields
Green Lantern (retro) – 23 shields
Martian Manhunter (modern) – 29 shields
Martian Manhunter (true) – 15 shields
Superman (black recovery suit) – 32 shields
Superman (Earth 2) – 65 shields
Superman (Kandor) – 91 shields
Wonder Woman (biker) – 61 shields
Wonder Woman (toga) – 44 shields
Zatanna (classic blue) – 25 shields
Zatanna (Identity Crisis) – 38 shields