The motion sickness, made it difficult to play Fallout 3 and it made Mirror's Edge near impossible to play.

I do but rarely get sick when playing FPS games.  I remember my last sickness i got it real bad playing CoD MW1, 4-player split screen.  I think it was due to the lighting in my room and the intense focus on a smaller screen got my brain fried.  My bro gets sick easily playing FPS tho.

I don't get sick with any game... Have never tried 3D, so I don't know about 3D games... but I doubt it.

I remember I used to get sick at games with bad graphics during the PS1 era (mostly the ones that didn't have static camera angles), I couldn't play anything that wasn't Resident Evil, Dino Crisis or Parasite Eve, etc, for more than 30 minutes. After 30 minutes I'd start sweating, couldn't keep my eyes open and feel like I was about to vomit. But I got used to the bad graphics after a while, I even managed to finish Medal of Honor 1 and 2 even though I didn't really like them :P. The last time this happened to me was with the Alone in the Dark demo on PS3, the graphics were so bad for me... but at least the demo didn't last long enough to make me feel too sick, lol.

The first time this happened to me (my first encounter with a FP game) was with Thief when it came out (this was on a PC). I was SO looking forward to this game, but after 5 minutes felt very ill. It was very frustrating, as I realized that I wouldn't be able to play this game that I really wanted to. Nowadays I manage longer stretches, but it's still touch and go, which is why I rarely play FP games.

I have never felt sick or none someone to feal in anyway abnormal whilst playing an fps xD

lol in just realised if 20% of people have have voted it does make them feel sick (thats what it was at time of me posting this) then there would have been like 4 million people making complaints about mw2...and yet there are none that i can see xD (or at least nor 4 million)

I don't have that problem but my wife does, she gets motion sickness very quickly, tha camera has to be very steady and the frame rate must be ultra high for her not to get sick. I also have a cousin with the same problem. I have another friends that has headackes when he plays those games. Don't know anyone else with the problem, but based on my limit anecdotical data I can say that maybe 10-15% of people has some kind of problem with motion sickness and First Person Games.

only on pc and on the wii but on the ps3 and xbox 360 am fine, the weird thing is, thing thend to get more shaky and i need to move the screen faster on both ps3 and 360

People who knows get sick with this kind of games DON'T BUY the games in the first place. So your estimates about 4 million complains lacks logic.

But lets create a more reasonable estimate. Let's say that 5 million of those copies of CoD MW2 where bought to or for people who had never in their lives play a FPS (yeah right). 20% is 1 million people in all the world and they don't usually play games because this is the first FPS they are playing so they don't complain in forums, also they felt some kind of discomfort and stoped playing, sell back the game, gave it to another person, or any other thing instead of just complain. We will have a very small amount of people really complaining about the game and many of those will complain with relatives, close friends and not in an internet forum, so is even less likely we will ever hear from then.

HL2 on PC made me sick, as did Metroid Prime.  I think it's probably the 60fps framerate combine with the quick movement.

Friend of mine, though, got sick playing Indiana Jones and the Emperor's Tomb of all games and had to quit.  Different strokes.

Oh, and didn't vote for any.  None of the options fit my feelings.