Contra is a freeware modification for Command and Conquer Generals: Zero Hour real-time strategy game. It's a big project started in 2004. It adds many new units as well as numerous new upgrades, new general's powers and buildings. It also adds new sounds, maps, bug fixes, enhanced graphics, and other effects, as well as three new generals.
AF Burton A-10 strike was annoying and overpowered in many cases. So his ability is changed and replaced with another unit. This fighter can take down a single unit without causing massive damage to nearby structures and units too. Unlike A-10, fighter is also affected by stealth upgrade.