Six Flags Great America and Six Flags Mexico have plans for an indoor, 4D “dark coaster” ride dubbed “Justice League: Battle for Metropolis”. Six Flags St. Louis is adding FIREBALL coaster for 2016 and Six Flags Great Adventure adds TOTAL MAYHEM 4D Free Fly Coaster. Six Flags Great Adventure also announced the start of its 2016 Season Pass sales with its special Flash Sale through Labor Day weekend, which features savings up to 65-percent off on 2016 passes. September 3 through September 7, guests will receive a free upgrade to a Gold Season Pass with every Pass purchased. Gold Season Dining Passes may be used at any Six Flags theme park. 2016 Season Passes provide unlimited visits to Fright Fest® and Holiday in the Park® at Six Flags Over Georgia in 2015 and all of 2016.