I've been playing with the 3DS all day for much longer than Nintendo's recommended allotment of time. My head isn't killing me, and I'm not barfing. Yet.
Gaming for me has always been about relaxing and unwinding. And I do think you can do that with the 3DS. You just need to know there is a sweetspot and that sweetspot is very small so do not step out of it. If you do, you might end up in headache city.
Okay, a couple of things. I have been up since very early this morning. I am tired, and my eyes are dry. As I said, because it's been a long day. But my aim isn't to bitch about playing the 3DS for an insane amount of time. No, it's to point out how you can possibly have a comfortable experience while playing the 3DS and enjoying the 3D effect. And if 3D makes you hurl, the portable looks great in 2D, so just switch it to that.
I know Nintendo and other game companies are being careful about the 3DS. It's not just that they don't want to get sued. Their advice about taking breaks from the 3D while playing seems pretty sound. You can ignore it. That's what I've been doing all day. I've been playing Nintendogs + Cats, Super Street Fighter IV 3D and the new Professor Layton game. Besides those, I've been checking out the on-board 3DS games that come pre-installed with the system.
Still, it's hard to unwind and just relax, but that will come. There is so much about the 3DS that is still unfamiliar, and I'm still trying to find my footing. This isn't a dig on the 3DS, but it's a new system and it naturally doesn't yet have that old comfortable shoe feeling.
The 3D effect on the 3DS is really great. I do actually like it. But I can feel my eyes working twice as hard to produce the effect. I've found that if I put the 3DS in my lap at arms length, keeping my head straight, but looking down my nose at the 3DS, I can hit that sweet spot pretty easy. It does require some fiddling with the 3DS slider.
My first couple of hours with the 3DS were spent with the 3D slider effect at full blast. Any time, I slightly moved the 3DS, the sweetspot was gone, and I was left with a blur of images and my brain trying to make sense of what I was looking at. It became a bit too much — difficult to process even. So much so that looking at a computer screen, which usually makes me tired, felt relaxing. I didn't get a headache, mind you, but it just felt like more effort was required.
But, I found that if you turn the 3D slider down, way down, you can still get the 3D effect, or damn near it, but with much less work. More 3D isn't necessarily better. More sleep is, though.