The $100 Nintendo Game Boy Micro--or GBM, as it has already been dubbed by the Nintendo faithful--lives up to its name. It's a minuscule 4 inches wide, 2 tall, and 0.7 deep--that's roughly the size of an iPod Mini or a small cell phone but bigger all around than Apple's "impossibly small" iPod Nano. The horizontal design is a departure from the squarish clamshell of the SP; in fact, the Micro looks more like a downscaled version of the old Game Boy Advance. To the right of the 2-inch-diagonal screen is a four-way control pad, while the two main A/B control buttons are to the left. Two shoulder buttons along the top edge round out the main controls. The Select and Start buttons are below the screen on an angled border.
Game cartridges slide into the bottom side of the Micro. (For the record, the Micro accepts only the recent Game Boy Advance titles, not the larger Game Boy Color or original Game Boy cartridges from decades past.) The slot is flanked on either side by the power switch and--hallelujah--a standard 1/8-inch headphone minijack. The latter corrects the most glaring flaw of the Game Boy Advance SP, which needed a small dongle to connect standard headphones to its proprietary port. If you don't have headphones, the small speaker on the Micro's front face will suffice. A tiny rocker switch on the right side controls volume. The rechargeable lithium-ion battery is found under a screwed-down cover on the rear and can be replaced by the user when it eventually poops out.
The SP has two small expansion ports on its rear, but the Micro has only one: a new proprietary connector, centered on the top edge between the shoulder buttons. At present, it's limited to providing a connection for the AC power adapter to recharge the battery, but it will eventually be used to connect to some forthcoming Micro-specific accessories. Nintendo plans two multiplayer link cables (for head-to-head Micro vs. Micro and Micro vs. SP connectivity) as well as a Micro version of the SP's wireless adapter. So, while none of the existing SP accessories will work with the Micro, it should eventually have the same multiplayer capabilities as its predecessor, assuming you're comfortable with extraneous link cables and bulky wireless adapters.
The Nintendo Game Boy Micro ships in three colors: black, silver, and a special 20th anniversary edition of Nintendo's Famicom system (the Japanese version of the NES). But those are just the unit's body color--the front is actually a swappable faceplate, à la the Xbox 360. The two original colors came with three swappable faceplates, while the special edition had just one. Like the company has done with its other portables and systems, Nintendo adds new colors quite frequently. While the Micro loses the clamshell design that provided screen protection for the SP, the faceplates cover the screen, so cosmetic scratches and scrapes are restricted to the surface. Expect to see a variety of faceplate packs from Nintendo or other third-party vendors in the future.
Aside from cosmetic variations, then, are there any significant differences between the Micro and the SP? In a word, no. The Micro is just the SP in a smaller package; it's not intended to deliver anything new in terms of gameplay or features. Even battery life is basically even, about 10 hours between charges. It comes down to which Game Boy delivers a better user experience. And while the answer is more subjective than absolute, we came down on the side of the Micro. Despite its overall smaller size, the Micro is actually 3/4 of an inch wider than the SP. The broader form factor combined with its lighter weight--3.1 ounces (with cartridge) vs. the SP's 5.3--yielded better overall ergonomics. Gaming sessions on the Micro were more comfortable and less fatiguing in the hands and fingers.
At just 2 inches, the Micro's small screen appears to be a liability; it's fully 33 percent smaller than the SP's 3-incher. When compared to the larger screens of the original GBA and the first models of the GBA SP, your eyes will probably gravitate to the Micro's brighter screen. Time has not been very kind to the Micro's design as many of Nintendo's other portables have caught up in terms of screen clarity. The GBA SP has been beefed up in the brightness department, and the redesign of the Nintendo DS--the DS Lite--offers up just as brilliant a screen.
Ultimately, the biggest knock on the Game Boy Micro is its price. More sophisticated gamers will want to spring for an extra $30 to upgrade to the DS Lite--it plays a growing list of popular titles and it's just as stylish as the Micro. Thriftier gamers will find the brighter version of the GBA SP a better deal for $20, especially since the system can play original Game Boy games. Until the system is available at a price befitting its feature set, we can't really recommend it to anyone.