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. There are lots of people playing in multiplayer.
Centurion is energy depending, rank 1 tank, which needs to be purchased through general's powers. This means, if you want him, you will need to spend one science point. Centurion consumes 2 energy points, and without energy he is shut down. His special hovering locomotor allows him to drive over water and cliffs. Fires energy shots which cannot be deviated by ecm. Centurion is good to deal vs. any rank 1 tank, but also, with upgrades at rank 3, he can improve his armor, and weapon. But, while improving weapon, he will need even more energy, specifically he will need 3 energy points in total to be online. So, be careful, this is a tricky unit. Standing near Ion Plant will give him additional +50% damage bonus, because he will consume energy directly from Ion Plant.