Earlier today, we saw gameplay footage from an unreleased Justice League video game that was being developed by Double Helix around 2010. You can check out that footage by clicking here, which features Batman going toe-to-toe with Superman.
That footage got me curious, so I did a bit of digging and uncovered some concept art that were created for the game by conceptual artist Darran Douglas Hurlbut. You can check out these character designs below of Batman, Green Lantern, Star Sapphire, Captain Cold, The Trickster, Mr. Freeze and Martian Manhunter.