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.
Since it's apparently not obvious enough, YOU ARE SUPPOSED TO LOSE. THERE IS NO WIN CONDITION. Before starting, make sure to read the Readme inside the Map Folder in order to get the Map working. Also, welcome to the first China Coop Mission for Contra! You can prove here, how much you care about every single Unit and also your Teammate. If you don't, it's going to be harder than usual.
Read the Readme File inside the Map Folder for more Details.