Free alternatives to games you'd otherwise pay for
For most paid classics there is a free, open-source equivalent that is genuinely good — not a knock-off. Every recommendation here has cleared the PlayBound Bar.
Command & Conquer
3 free options · also Red Alert
Age of Empires
3 free options · also Age of Empires II
Supreme Commander
3 free options · also Total Annihilation
Cities: Skylines
3 free options · also Transport Tycoon
Minecraft
3 free options · also Minecraft Java Edition
Factorio
3 free options · also Satisfactory
Worms
2 free options · also Worms Armageddon
Mario Kart
2 free options · also Mario Kart 8
Quake & Unreal Tournament
2 free options · also Quake III Arena
Diablo
3 free options · also Diablo IV
Elite Dangerous
2 free options · also Escape Velocity
Super Mario Bros.
2 free options · also Super Mario World