Half-Life: Z-Virus Mod is a free-to-play mod that recreates the famed Zombie Scenario campaign from the online action game Counter-Strike Nexon: Zombies. Instead of purchasing the collaborative effort between Valve and Nexon Korea, you can experience the same fast-paced action as an activatable add-on to your existing Half-Life (HL) game.

As a retelling of the original campaign, expect Half-Life: Z-Virus Mod to take a couple of liberties. It doesn’t adapt the entire campaign, but it has a lot of new and custom content. For other immersive experiences, try Half-Life: Echoes Mod or Half-Life: Decay Mod.

Escape the Rex Labs once more

Half-Life: Z-Virus Mod is a good adaptation of CS: Nexon, itself a zombie-themed spinoff of the classic Counter-Strike and Half-Life games. In terms of premise, it tries to be faithful to the original. You start at the Rex Laboratory, training as a part of its soldier program. In a story progression similar to the original Half-Life, you are tasked with making it out alive of the facility.

Expect the arsenal from Nexon: Zombies to be on full display in this game. Instead of the sci-fi weapons from the original Half-Life, it opts for the more extensive global weapons from the online Counter-Strike game. You can expect to find Dual Elites, the Triple Threat shotgun, or the Korean K2C assault rifle. This lets you play the game over and over again, with zombies and military-themed enemies.

It’s worth noting that in order to play this mod, you have to have the Steam version of Half-Life. Players who obtained a copy of the Valve game from other sources complain about the add-on not working. Additionally, it has 10 distinct maps of varying sizes, making the game good for an hour of gameplay. While you don’t have PvP and PvE, you get a fulfilling single-player adventure instead.

Just as action-packed as the original

While Nexon: Zombies’ appeal partly comes from its online multiplayer nature, Half-Life: Z-Virus Mod takes a different direction—and surprisingly works. Recreating familiar environments, throwing in a new set of enemies, and letting players use a wide range of weapons all make the single-player adventure fun for an entire hour or so. If you have the Steam version of Half-Life, there’s no reason not to try this one out.