You are better of calling these experimental games. Art games they are not.
In my opinion, "Jetlag" is something in between. It's experimental art.
And what modern piece of art hasn't been experimental?
By the way: The things Movius described actually make it art:
There are certain motives the creator worked with when creating "Jetlag".
Maybe you can't play Jetlag for a long time, but having played it two or three times you realize certain ideas behing it. That's what art is about.
Maybe we can even draw a line between modern and nonmodern art in video games?
If you take something like a... Van Gogh Painting (or even a renaissance piece of art) you can watch it for hours and it's motives aren't clear. The whole thing just touches you as a human. That's why it's best to hang them into your room and look at them over and over again.
Games like Shadow of the Colossus or Okami may represent that artform.
On the other hand: Modern art really transmits certain ideas. (That's what makes it different from... say... expressionistic/impressionistic art)
"Jetlag" does that, "Gravitation" does that.
What do you think about that idea?
BaronCid