''You have to give Vicarious Visions some credit. Bringing the Guitar Hero experience to the portable DS was not an easy accomplishment. The developers at Vicarious Visions' solution to the problem comes in the form of a plug-in fret controller that fits into the DS system's GameBoy cartridge port. Innovative, yes, but not very ergonomic. Playing more than three songs in a row will put you in imminent danger of developing chronic carpal tunnel syndrome.
The problem is in the way your DS needs to be held to play the game. The DS is held sideways in the palm of your left hand with your fingers bent at a 90 degree angle and resting on the fret buttons. You also need to keep the spine of the DS braced against your palm to keep it from moving too much as you push the fret buttons. In most playing positions, your wrist will be bent to keep the DS oriented upright, or you need to twist your head while playing to get a good look at the screen. If you don't think that this would be painful, trying playing two or three songs this way and then get back to me. Searing wrist pain and kinks in various parts of your body occur with every play session. About the only way to play without too much discomfort is with your arm flat on a high desk (or on a high countertop while standing) and with your wrist kept perfectly straight. Which, of course, means that the game isn't really that portable after all.''