If you slept on last year's City Life, one of the best civil engineering simulations since 1989's groundbreaking Sim City, wake up and smell the urban squalor. World Edition, a new stand-alone expansion pack, doesn't just add extra scenarios and maps. It introduces action-enhancing features -- including in-game MP3 support -- so you can enjoy your favorite tunes mid-mission. It boasts global monuments, including the Eiffel Tower and Statue of Liberty.

The cumbersome interface, with its incomprehensible array of charts and buttons, limits World Edition's appeal to only dedicated enthusiasts willing to master its significant learning curve. The 300-plus constructible structures (skyscrapers, gas stations, grocery stores) and gorgeous 3D landscapes, more than ever make it worth pushing through the pain. Regardless of where you place airports, offices and housing, you will not please all of your citizenry, a touchy bunch divided into six largely incompatible subcultures from Elites to Blue Collars. But the game's cerebral thrills have only grown better with time, thanks in no small part to the inclusions made here and ongoing fan community support for homemade content created via a built-in software editor.

By no means a mandatory purchase for casual shoppers (a shame considering the program's catchy theme), diehard City Life: World Edition enthusiasts will find the unparalleled depth and near-infinite replay value a welcome choice. Longtime fans can't help but appreciate the subtle tweaks, enhancements and bonus content, even as neophytes marvel at their newfound ability to shape a living, breathing and internationally diverse digital metropolis. Call it cutting-edge "edutainment," or simply the modern urban planning major's consummate tax write-off.