Do you play Animal Crossing New Leaf in 3D? Not me. It feels like your brain is split into two when you turn it on. I could not stand it for even five seconds. I always have the 3D turned off.
I'm one of the very few who doesn't get a headache when I use 3D, so sometimes I do use it. But I'll only switch it on if I'm sitting comfortably, otherwise it becomes a nuisance when you tilt the screen even a tiny amount and it becomes blur-land.
My eyesight isn't the greatest and it takes me ages to find the perfect angle to view it from since I realise that I am not looking at the screen straight-on whenever I switch on 3D so, no.
It doesn't give me a headache, but I rarely use it. I use it when I'm hunting on the island while relaxing in bed at night. This is the only time I can hold it perfectly still, as unfortunately, you have to focus on one spot.
I guess that's why Nintendo is coming out with a new console which will gyrate. I wish they had thought of this in the first place, as I'm guessing not many of us are going to run out and spend another €200/$200 on a new console anytime soon.
Wow I'm surprised at all these responses! I must be one of the lucky few, but I have no trouble comfortably playing in 3d for hours. I think the game looks WAY better in 3D (I cringe at the 2Dness). The extra depth really helps make the town feel like a living, tangible place. 2D is just flat and...meh