While .rar files often circulate on abandonware sites, the game is officially available and maintained on modern storefronts:

Common bugs include seeing through walls, flickering shadows, and unstable frame rates on modern GPUs.

: Includes Steam Achievements and integrated multiplayer support.

For those wanting the original level design before the "Classic" rebalancing, the Rune Extended mod can restore cut levels and further improve stability. Where to Find the Game