Warzone 2100

"Warzone 2100 is a free, open-source, 3D real-time strategy game that was initially released in 1999. Players navigate a post-apocalyptic world, commanding advanced military units in intense battles to secure resources and complete mission objectives. With a focus on tactical warfare and strategic resource management, absurdly fun gameplay and countless hours of single player campaign, Warzone 2100 offers a unique and immersive RTS experience."