Virtual Boy was nintendo's stab at a Virtual reality game system. People complained of headaches, it had almost no games, what games it did have were nominal and had very little replay value (ok thats my opinion but it seems to be shared by the majority) and had horrible color/graphics. Of course Virtual Reality is a newer technology (makes me think back to when nintendo had a power glove and those wireless controllers before infarred technology became super cheap and actually decent) and is REALLY expensive, so w/o nintendo having a machine that sold for thousands of dollars I guess they just used a red/black scale of colors and failed miserably.
What I think is sad about the whole thing is now I bet nintendo and other developers are gun shy and when vr technology becomes cheaper and more advanced the flop of the virtualboy may steer developers away from virtual reality.... hopefully though they'll try again in the future. Of course, I'm still hopeing for a data glove that has game support and works well.........