Nintendo of Japan has pointed out that neither the forthcoming Game Boy Advance SP nor the Game Boy Player peripheral will work with games that use the built-in tilt sensor. This means that writers' favourite Koro Koro Kirby (Kirby's Tilt 'n' Tumble to you and I) will be off limits.
Why? Well, the GBA SP's cartridge slot is the wrong way up (you insert the games into the front of the bottom half of the unit, facing down), which is bound to confuse the sensor inside the cartridge. And as for the Game Boy Player... well, tilting requires movement, doesn't it?
Nintendo also hastens to point out that the GB Player will not work with the Panasonic Q GameCube/DVD hybrid. Physically.
In slightly more exciting news, Ninty has announced plans to ship 300,000 units of the new GBA SP to Japan for its February 14th release.