The "Expensive Experiment", Giant Tank, is the boss of Mission 6 in Double Dragon Neon. It is a gigantic tank equipped with several weapons, similar to the tank boss from Double Dragon II: The Revenge.
The fight against the Giant Tank takes place in three phases, each of which ends when its glowing red weak point takes enough damage. During the first phase, players must climb to the top of the tank while destroying its weapons or avoiding their attacks, as well as the Williamses who appear to defend it. During the second phase, the Killacopter flies in and fires homing missiles to support the Giant Tank. During the third and final phase, missile launchers open above the tank's treads and start firing missiles upward, giving players another hazard to avoid.