Don't call them nonplussed, though. Key digital storefronts , , and --all three boasting comparable games software catalogues--have responded by stating they simply won't carry Activision's first-person modern military shooter. Their rationale? Put it this way: Would Walmart sell retail products that required the customer periodically drop by Kmart or Target for service, support, or just basic use?

"We don't believe games should force the user to install a Trojan Horse," a spokesperson for Direct2Drive . The company's no longer offers pricing or game information, and instead displays the following notice:

At Direct2Drive, we believe strongly that when you buy a game from us, you shouldn't be forced to install and run a 3rd party software client to be able to play the game you purchased. Because COD MW 2 requires you, the consumer, to do that, we aren't able to offer the game via Direct2Drive at this time.

"We share some of the same concerns as Direct2Drive over the bundling of the Steam client with the game," an Impulse spokesperson . "The most obvious issue is the forced inclusion of a competitor's store that blocks us from carrying the game."

Steamworks, it's important to note, isn't synonymous with Steam. Steam comprises Valve's combination online storefront and social gaming network, a relatively low-impact wrapper that embeds itself in your operating system and puts its tendrils into your gaming environment. The Steam client is necessary not just to purchase games from Valve, but also to play them thereafter. Without the Steam client and steady online access, games can't be purchased, downloaded, played, backed up, or restored.