The 1976 Atari arcade game Starship I had me at the words "Sensors detect another quarter in your pocket, deposit it to be the captain of Starship 1." From then on I was hooked, and the shopping mall arcade became my paradise. In Columbia, Missouri, I found my Arcadia in Gunther's Games, a highly stylized and sprawling place. The floor was laid with cobblestones to look like an old street, complete with lamppost, and one wall was covered in a façade of a Brooklyn brownstone with windows and a partial fire escape. They sold soda pop and snacks and every Sunday you got 30 tokens for $5. I spent my college years there rocking the sticks.

Few arcades like Gunther's are still around these days. Home consoles have destroyed the arcade business in the U.S.; good luck finding one at the mall anymore, and even Gameworks molders away downtown. Gunther's still lives, amazingly enough, but such beacons of video joy are few.

Thanks to Microsoft, though, a new beacon has lit up: the Xbox Live Arcade. The version of the online arcade on the original Xbox wasn't much to get excited about, but on the Xbox 360 Live Arcade has become something really promising. To see just how promising, download the demo of Geometry Wars: Evolved and then shell over the five dollars it takes to make it yours.

Some people say Geometry Wars was the best game on the 360. It may be the most intoxicating. A top-down, 2-D arcade game, retro in concept but modern in execution, you use one joystick for movement and one for firing, just like the old Robotron, but the pace starts fast and turns explosive. The visuals and sounds are thrilling despite their 2-D nature, making for a highly polished experience more fun than many of the full-on games I've reviewed in these pages.

Retro gaming rules on Live Arcade. The second-best-selling title is Gauntlet, the old four-player arcade game, now playable online. Joust, Robotron, Smash TV, and Crystal Quest are there as well, their graphics redone to work on HD television sets, but each still looking exactly as you remember. Retro-ish new games like the platforming treat Wik and the vertical shooter Mutant Storm Reloaded are also a blast. And this March, 1992's Street Fighter II Hyper Fighting will return, also with online multiplayer support.

The early excitement generated by Geometry Wars has accompanied word that major game publishers are looking at developing similar low-cost, high-fun titles for the service. Developers weary of three-year product cycles and teams of 70 people like the sound of a six-month, four-person project with no retail headaches and no piracy. And the medium desperately needs a renaissance of creativity—games today are lumbering beasts, and in the same time it takes to make a typical high-end game, the original arcade creators went from Space Invaders to Galaxian to Galaga. Live Arcade may just be the perfect way to let video-game fun mutate and metastasize again.

Sensors detect another quarter in your pocket. It's time to play.