WW4 Extended is an unofficial expansion for the WW4 modpack, the OFP & CWA mod that focus on performance. It covers modern, Cold War era and Arctic warfare, adding numerous infantry units and vehicles for all sides, and provides several visual and sound effects (tracers, bullet cracks), support options and many other features.
US arctic infantry vs AT-ATs (spoiler: they lost). AT-ATs by Macser (and they are not included in WW4 Extended). Terrain is Winter Kodiak.