US PC game charts: July 30-August 5

For the last week of July, THQ's Cars: Radiator Springs Adventure vaulted to the top of the best-selling PC games list. Cars' feat was all the more impressive because it sold more copies than not only 2K Games' high-profile newcomer, Civilization IV: Warlords, but also Blizzard's massively multiplayer online role-playing heavyweight, World of Warcraft.

The first week of August, however, saw the Pixar movie tie-in fall sharply, from first to sixth--leaving an opening for World of Warcraft to once again retake the top slot, according to the latest sales statistics from NPD Funworld. Electronic Arts' long-standing virtual-life simulator The Sims 2, at fourth last week, moved ahead to number two.

The week also saw the return of Half-Life 2: Episode One, which last appeared, at number five, on the retail charts during the week of July 2 to 8. In reality, Episode One--the first of three planned add-ons to Valve Software's 2004 first-person shooter Half-Life 2--likely sold many more copies than this week's charts position indicates. NPD Funworld's sales figures only count boxed games sold in retail stores--but Episode One receives a substantial portion of its sales from Steam, the Bellevue, Washington-based developer's digital-distribution platform.

In its second week on the charts, Civilization IV: Warlords showed resiliency, dropping only one place to number three, after it joined Cars last week for a short-lived reign atop World of Warcraft.