After 20+ years, Zombie Panic! Source—a Half-Life mod—releases on Steam. Its appeal stems from asymmetric gameplay: humans wield powerful weapons but face inventory limits (carrying too much slows movement), while durable zombies threaten in swarms. A panic mechanic lets survivors dump items for temporary speed boosts to escape. This high-risk/high-reward interplay creates engaging moments when human firepower balances against zombie durability and proximity danger.