I was very skeptical when I unpacked this; it looked so thin that I was pretty annoyed and certain I would have to return it. However, I put it on a wood floor, knelt on it, and didn't feel anything but cushion. And I am a big woman! Also, I have a Tempurpedic Mattress so I'm pretty spoiled when it comes to sleeping surfaces and foam mattresses.
I bought this specifically with tanning outside on my deck in mind. I also love lying on the floor when watching TV, but my hipbones, ribs, elbows, etc., get horribly achy. I was a little concerned that for a fraction of the price I could have bought a mattress topper or camping pad that would have served just as well, but the "Game Terrain" is a much better size. It has a white plastic cover over the foam (but it's soft and comfy, doesn't crackle or smell like chemicals), which is even MORE perfect for tanning because it doesn't seem to be too absorbent or delicate, and it can be wiped with a sponge. Because of the warm weather, I haven't put the "real" cover on yet--it's luxurious super-soft micromink on one side, and black ripstop nylon on the other. Another bonus--you can put this on the floor or carpet and it won't pick up dirt or fuzzies! If my son has a friend spend the night, I don't feel like a jerk offering this as a guest bed.
For a real treat, use this in your home gym for yoga and Pilates! It's twice as wide as a regular exercise mat and way better for your bones. Then after your last sit-up you can just lie back and take a nap.... :D
PS--be very careful when unpacking! It comes folded very small and wrapped very tightly in layers of plastic and miles of tape. In spite of my best efforts, I nicked a bit of the white material.