A few weeks ago, this column discussed an intriguing puzzle game called "Braid". The game is interesting not only for its intelligence, but also for the way it has been distributed. Gamers could simply download a demo from the Xbox Live Arcade service; if they liked it enough, they could unlock the complete game with a few more clicks and a credit card. This may not seem so remarkable, given our familiarity with iTunes and video-on-demand. But while downloadable gaming has been a staple of PC gaming for years, console manufacturers have been slow to adopt this as a business model. Lately, however, downloadable games are becoming more common, leading designers to rethink what it means to create a successful game.

The big console manufacturers, such as Sony and Nintendo, now all have their own online-gaming networks. Gamers can now download everything from decades-old classics to fully-fledged, 3D high-definition gaming experiences with a few button-clicks, and play them all on the same machine from the comfort of their couches. Given the level of technical complexity available on these consoles, it is perhaps surprising that the most successful downloadable niche so far consists of fast, pick-up-and-play games that provide brief and simple bursts of addictive fun.

For example, Activision recently released "Geometry Wars: Retro Evolved 2" to considerable acclaim. The game's first iteration, as the flagship of Microsoft's Xbox Live Arcade service, was seen by many as the reason to pony up the $300-400 to own the high-powered, high-definition Xbox 360 in the first months after its launch in 2005, in spite of the fact that it was a 2D game with minimalist graphics that was available for $5.

The success of "Geometry Wars" is simple: razor-sharp gameplay reduced to absolute basics. Its rules are intuitive and its controls are nearly rudimentary. It turns out it is surprisingly satisfying to take control of a "ship" (essentially a squiggle on the screen) that is under relentless assault by green squares, purple bowties, blue diamonds and little orange rocketship shapes. Failure is inevitable, but the goal is to earn an ever-higher score for lasting a few seconds longer than the last game. The latest iteration of the game--now $10--offers players a variety of different gameplay modes (eg, the "Pacifism" mode leaves a player weaponless, but grants the ability to fly through "gates" that destroy all surrounding enemies).

It's hard to describe just how addictive this game is. Moreover, each game lasts only a few minutes--or seconds, if you're new to it. But it's so quick and easy to jump back into the action that I find myself looking up after a heated session to find that hours have passed, and my hands are cramping into claws. 

The true, addictive brilliance of the game is the "high score" notation at the top of the screen. Instead of displaying the highest score in the world (which is invariably some unattainable monstrosity), it features a score achieved by a friend of the player, provoking some healthy rivalry among friendly gamers. A high score in lights is a familiar sight to anyone who has haunted old videogame arcades; reimagining such classic features is now a significant area of exploration for designers of downloadable games.

The effect of all of this has been to expand the definition of a successful game release. Traditionally, games have had to compete for shelf space, jockeying for position before a fickle consumer's eye. The upshot has long been a homogenization of options, whereby competitors chase the success of market leaders with "me-too" games. When "Super Mario Brothers" and "Sonic" led the market, the industry was awash in animal mascots, each more ersatz and sassy than the last. More recently, the success of the "Halo" and "Grand Theft Auto" series have led to a glut of first-person shooters and "open world" games.

Downloadable games, which bypass all of the costs associated with the manufacture and sale of physical products, can achieve financial success without generating nearly the same amount of revenue as a larger game release. So quirky concepts that would never be approved for retail products can reach their small but often fervent audiences. Games such as "Geometry Wars" and "Braid" on the 360 and the "Pixeljunk" series on the PlayStation have generated significant sales and buzz in the industry, without ever appearing on a store shelf or selling a million units. 

If the future is as virtual as most technology pundits would claim, it seems likely that we will see more diversity in the size, scope, and experiences that are available to gamers. That means that one day there may be a game out there for everyone who cares to play.

Picture credit: "Geometry Wars"

(Brett McCallon is a writer based in New Orleans. His last gaming column was about chasing loot in "Too Human".)