I wonder whether the kitten has some kind of medical problem.

even the pads. Mine were always pink, but these look really too bright a red to me.

Kittens can go from 90 to 0 in seconds.

just instantly collapse. It was so cute and funny to see it happen. I hope that's what happened with this kitty.

They pass out for a quick kitty nap and they're back up drag racing in no time. To me, the kitten looked rather sleepy while she was playing with her littermate.

When you see the human fingers, notice how salmon-red they are -- nearly the same color as those pink kitten toes. Human skin is rarely that red, so subtract the excess, artifact redness and those toes, tongue and lips are just fine. It only seems to happen when I have certain light bulbs (specifically, 2700K CFLs) in the fixtures.

Having had kittens that would run-run-run-run-fall-over-sleep-hard-run-run-run (not the mention 8 sibs that did the same damn thing equivalent baby age)... This is what infant mammals do.

He was up there in years and having kidney problems. We saw him laying stone still under the table and my wife said he had passed. We both got teary eyed and began to remember this and that about him and what a good cat he was going on and on with both of us petting what we thought was his now empty shell. Then he burped, opened one eye , stretched out and walked into the kitchen. Damn, miss that cat every day.

I think happy kittens do this when they are "good" with each other, and sometimes with their humans.

MMM