Hundreds of buyers of "Half-Life 2," the hotly anticipated shooting game released last week, are reporting in developer Valve Software's that they feel queasy and often develop a bad headache after playing the game for as little as an hour.

Far from sounding aggrieved, enthusiastic players greet the incipient hurling as evidence of the game's sophisticated graphics. "I am impressed and sickened (literally) by the level of detail," one player wrote.

Players have all kind of theories for beating the curse of the green gills, from taking Dramamine 30 minutes before playing the game to adjusting monitor settings to avoid possible conflicts with overhead lights.