"Half Life 2 makes me want to die, I feel so ill. I think it's to do with the 'tunnel vision'- it doesn't provide such a broad view, compared to other games. Also, I have a strange reaction to coloured tints in games, for example, in Mario Galaxy when teh screen is tinted purple for the purple coin challenge I found it unbearable. THis also applied to fallout 3 with Green tint (tho a mod removes that), so it could be that."
SMG did make me a bit queasy, now that you mention it.